Chairman Sen. Lamar Alexander (R-TN) removes his plaid face mask as he prepares to begin a Senate Health Education Labor and Pensions Committee hearing on new coronavirus disease (COVID-19) tests, on Capitol Hill in Washington, U.S., May 7, 2020. Andrew Harnik/Pool via REUTERS

Chairman Sen. Lamar Alexander (R-TN) removes his plaid face mask as he prepares to begin a Senate Health Education Labor and Pensions Committee hearing on new coronavirus disease (COVID-19) tests, on Capitol Hill in Washington, U.S., May 7, 2020. Andrew Harnik/Pool via REUTERS

Chairman Sen. Lamar Alexander (R-TN) wears a plaid face mask before a Senate Health Education Labor and Pensions Committee hearing on new coronavirus disease (COVID-19) tests, on Capitol Hill in Washington, U.S., May 7, 2020. Andrew Harnik/Pool via REUTERS

Chairman Sen. Lamar Alexander (R-TN) wears a plaid face mask before a Senate Health Education Labor and Pensions Committee hearing on new coronavirus disease (COVID-19) tests, on Capitol Hill in Washington, U.S., May 7, 2020. Andrew Harnik/Pool via REUTERS

Former Green Party co-leader Caroline Lucas and Labour's shadow business secretary Rebecca Long Bailey look at Plaid Cymru leader Adam Price as he sepeaks during a general election debate in Cardiff, Britain November 29, 2019. REUTERS/Hannah McKay/Pool

Plaid Cymru leader Adam Price speaks during a general election debate in Cardiff, Britain November 29, 2019. REUTERS/Hannah McKay/Pool

Former Green Party co-leader Caroline Lucas looks as Plaid Cymru leader Adam Price speaks during a general election debate in Cardiff, Britain November 29, 2019. REUTERS/Hannah McKay/Pool

BBC presenter Nick Robinson speaks in front of Plaid Cymru leader Adam Price, former Green Party co-leader Caroline Lucas, Labour Party's shadow business secretary Rebecca Long Bailey, Conservative Party's Chief Secretary to the Treasury Rishi Sunak, Brexit Party chairman Richard Tice, SNP leader and Scottish First Minister Nicola Sturgeon and Liberal Democrat leader Jo Swinson before a general election debate in Cardiff, Britain November 29, 2019. REUTERS/Hannah McKay/Pool

Plaid Cymru leader Adam Price, former Green Party co-leader Caroline Lucas, Labour Party's shadow business secretary Rebecca Long Bailey, Conservative Party's Chief Secretary to the Treasury Rishi Sunak, Brexit Party chairman Richard Tice, SNP leader and Scottish First Minister Nicola Sturgeon and Liberal Democrat leader Jo Swinson pose before a general election debate in Cardiff, Britain November 29, 2019. REUTERS/Hannah McKay/Pool

Plaid Cymru leader Adam Price, Labour leader Jeremy Corbyn and Green Party Co-Leader Sian Berry stand before the start of the Channel 4 News' General Election climate debate at ITN Studios in Holborn, central London, Britain November 28, 2019. Kirsty O'Connor/Pool via REUTERS

Krishnan Guru-Murthy, Liberal Democrat leader Jo Swinson, SNP leader Nicola Sturgeon, Plaid Cymru leader Adam Price, Labour Party leader Jeremy Corbyn and Green Party Co-Leader Sian Berry, stand next to ice sculptures representing the Brexit Party and Conservative Party who didn't appear at the event, before the start of the Channel 4 News' General Election climate debate at ITN Studios in Holborn, central London, Britain November 28, 2019. Kirsty O'Connor/Pool via REUTERS

Liberal Democrat leader Jo Swinson, SNP leader Nicola Sturgeon, Plaid Cymru leader Adam Price, Labour Party leader Jeremy Corbyn and Green Party Co-Leader Sian Berry stand before the start of the Channel 4 News' General Election climate debate at ITN Studios in Holborn, central London, Britain November 28, 2019. Kirsty O'Connor/Pool via REUTERS

Liberal Democrat leader Jo Swinson, SNP leader Nicola Sturgeon, Plaid Cymru leader Adam Price, Labour Party leader Jeremy Corbyn and Green Party Co-Leader Sian Berry, stand next to ice sculptures representing the Brexit Party and Conservative Party who didn't appear at the event, before the start of the Channel 4 News' General Election climate debate at ITN Studios in Holborn, central London, Britain November 28, 2019. Kirsty O'Connor/Pool via REUTERS

Plaid Cymru leader Adam Price stands before the start of the Channel 4 News' General Election climate debate at ITN Studios in Holborn, central London, Britain November 28, 2019. Kirsty O'Connor/Pool via REUTERS

Plaid Cymru's leader Adam Price is pictured outside of the Cabinet office, London, Britain, January 17, 2019. REUTERS/Toby Melville

Plaid Cymru's leader Adam Price is pictured outside of the Cabinet office, London, Britain, January 17, 2019. REUTERS/Toby Melville

A plaid blazer hangs at a Maje store at a shopping mall in Hong Kong, China November 12, 2018. REUTERS/Bobby Yip

Scottish National Party's leader in the House of Commons Ian Blackford, Britain's leader of the Liberal Democrat party, Vince Cable, member of the Welsh party Plaid Cymru Liz Saville-Roberts and Green MEP for the South West Molly Scott Cato meet with European Union's chief Brexit negotiator Michel Barnier in Brussels, Belgium October 25, 2018. REUTERS/Yves Herman/Pool

Scottish National Party's leader in the House of Commons Ian Blackford, Britain's leader of the Liberal Democrat party, Vince Cable, member of the Welsh party Plaid Cymru Liz Saville-Roberts and Green MEP for the South West Molly Scott Cato meet with European Union's chief Brexit negotiator Michel Barnier in Brussels, Belgium October 25, 2018. REUTERS/Yves Herman/Pool

Scottish National Party's leader in the House of Commons Ian Blackford, Britain's leader of the Liberal Democrat party, Vince Cable, member of the Welsh party Plaid Cymru Liz Saville-Roberts and Green MEP for the South West Molly Scott Cato meet with European Union's chief Brexit negotiator Michel Barnier in Brussels, Belgium October 25, 2018. REUTERS/Yves Herman/Pool

Plaid Cymru's leader Adam Price speaks at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Plaid Cymru's leader Adam Price speaks at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon listens to Plaid Cymru's leader Adam Price speak at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Plaid Cymru's leader Adam Price speaks at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon listens to Plaid Cymru's leader Adam Price speak at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon listens to Plaid Cymru's leader Adam Price speak at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon greets Plaid Cymru's leader Adam Price at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon waves with Plaid Cymru's leader Adam Price at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Scotland's First Minister Nicola Sturgeon applauds Plaid Cymru's leader Adam Price at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

Plaid Cymru's leader Adam Price speaks at the Scottish National Party's party's conference in Glasgow, Scotland, Britain, October 8, 2018. REUTERSRussell Cheyne

The facial reactions of an unidentified man (center) in a plaid shirt standing behind U.S. President Donald Trump led to the man's ejection from where he was standing and then went viral on the internet as videos spread of his reactions at the president's words at a "Make America Great Again" rally in Billings, Montana U.S., September 6, 2018. Picture taken September 6, 2018. REUTERS/Kevin Lamarque

Le procureur spécial américain Robert Mueller poursuit son enquête sur l'ingérence russe dans l'élection américaine de 2016, la liste suivante regroupe les personnes mises en examen, condamnées ou ayant plaidé coupables à des accusations criminelles. embed code and instructions: https://reut.rs/2LA09WK

The leader of Plaid Cymru, Leanne Wood, is approached by Scotland's First Minister Nicola Sturgeon, at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, is embraced by Scotland's First Minister Nicola Sturgeon, at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, is embraced by Scotland's First Minister Nicola Sturgeon, at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, is applauded by Scotland's First Minister Nicola Sturgeon, at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, stands with Scotland's First Minister Nicola Sturgeon, at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, gestures at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

The leader of Plaid Cymru, Leanne Wood, speaks at the Scottish National Party (SNP) conference in Glasgow, Scotland, October 9, 2017. REUTERS/Russell Cheyne? ?

Placards lie on chairs after Leanne Wood, Leader of Plaid Cymru, launched her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru poses for pictures at the launch of her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Placards lie on chairs after Leanne Wood, Leader of Plaid Cymru, launched her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Leanne Wood, Leader of Plaid Cymru launches her party's election manifesto in Rhondda, Wales, Britain May 16, 2017. REUTERS/Rebecca Naden

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon (L) and the leader of Plaid Cymru Leanne Wood acknowledge delegates following Wood's speech during SNP's annual conference in Aberdeen, Scotland October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon (L) reaches towards the leader of Plaid Cymru Leanne Wood following her speech during SNP's annual conference in Aberdeen, Scotland, October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon (L) applauds the leader of Plaid Cymru Leanne Wood following her speech during SNP's annual conference in Aberdeen, Scotland, October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon applauds the leader of Plaid Cymru Leanne Wood (not seen) following her speech during SNP's annual conference in Aberdeen, Scotland, October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon (L) and the leader of Plaid Cymru Leanne Wood acknowledge delegates following Wood's speech during SNP's annual conference in Aberdeen, Scotland, October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party's (SNP) annual conference in Aberdeen, Scotland, October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party's (SNP) annual conference in Aberdeen, Scotland October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party's (SNP) annual conference in Aberdeen, Scotland, October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party (SNP) annual conference in Aberdeen, Scotland, October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party's (SNP) annual conference in Aberdeen, Scotland, October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Leader of Plaid Cymru Leanne Wood speaks during the Scottish National Party's (SNP) annual conference in Aberdeen, Scotland, October 17, 2015. Scottish leader and leader of the Scottish National Party (SNP) Nicola Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne

Scotland's First Minister and leader of the Scottish National Party (SNP) Nicola Sturgeon listens to Leanne Wood leader of Plaid Cymru speak during the SNP's annual conference in Aberdeen, Scotland, October 17, 2015. Sturgeon will accuse Prime Minister David Cameron of playing 'fast and loose' with Britain's place in the European Union on Saturday, criticising his renegotiation strategy before a public vote on remaining an EU member. Britain's future in Europe has become a defining issue for the country. Cameron has promised to negotiate new membership terms before holding a referendum by the end of 2017 on whether to leave the EU. REUTERS/Russell Cheyne