A practice canvass of colours with varnishes made by paintings conservators while working on the conservation of 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana is seen at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

A paintings conservator uses a palette of oil paints while working at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Maria Canavan holds her palette of oil paints while working on the conservation of 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Maria Canavan holds her palette of oil paints while working on 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Maria Canavan holds her palette of oil paints while working on 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Maria Canavan holds her palette of oil paints while working on the conservation of 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Maria Canavan holds her palette of oil paints while working on the conservation of 'The Visit of the Queen of Sheba to King Solomon' by Lavinia Fontana at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Letizia Marcattili works on the conservation of a painting by Jacopo Palma il Vecchio at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Letizia Marcattili works on the conservation of a painting by Jacopo Palma il Vecchio at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Letizia Marcattili works on the conservation of a painting by Jacopo Palma il Vecchio at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Letizia Marcattili works on the conservation of a painting by Jacopo Palma il Vecchio at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Paintings conservator Letizia Marcattili works on the conservation of a painting by Jacopo Palma il Vecchio at the National Gallery of Ireland, as a phased reopening following Government guidance begins, after an extended lockdown due to the coronavirus disease (COVID-19) outbreak, in Dublin, Ireland, May 10, 2021. REUTERS/Clodagh Kilcoyne

Candidate Shaun Bailey of the Conservative Party gives a speech after Mayor of London Sadiq Khan is re-elected in the London mayoral election, at the City Hall in London, Britain, May 8, 2021. REUTERS/Henry Nicholls

Candidate Shaun Bailey of the Conservative Party gives a speech after Mayor of London Sadiq Khan is re-elected in the London mayoral election, at the City Hall in London, Britain, May 8, 2021. REUTERS/Henry Nicholls

Candidate Shaun Bailey of the Conservative Party gives a speech after Mayor of London Sadiq Khan is re-elected in the London mayoral election, at the City Hall in London, Britain, May 8, 2021. REUTERS/Henry Nicholls

Candidate Shaun Bailey of the Conservative Party gives a speech after Mayor of London Sadiq Khan is re-elected in the London mayoral election, at the City Hall in London, Britain, May 8, 2021. REUTERS/Henry Nicholls

Jill Mortimer of the Conservative Party speaks to reporters after voting results were announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party speaks to reporters after voting results were announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party speaks to reporters after voting results were announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party reacts after voting results were announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party speaks with Paul Williams of the Labour Party at Mill House Leisure Centre as voting results are announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party delivers a speech at Mill House Leisure Centre as voting results are announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party delivers a speech at Mill House Leisure Centre as voting results are announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party reacts at Mill House Leisure Centre as voting results are announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of the Conservative Party reacts at Mill House Leisure Centre as voting results are announced, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of Conservative Party looks at a staff member at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of Conservative Party waits at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of Conservative Party waits at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer (C) of Conservative Party waits at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer of Conservative Party arrives at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Jill Mortimer (C) of Conservative Party arrives at Mill House Leisure Centre as ballots are being counted, in Hartlepool, Britain May 7, 2021. REUTERS/Lee Smith

Canada's Conservative Party leader Erin O'Toole speaks during Question Period in the House of Commons on Parliament Hill in Ottawa, Ontario, Canada May 5, 2021. REUTERS/Blair Gable

Canada's Conservative Party leader Erin O'Toole speaks during Question Period in the House of Commons on Parliament Hill in Ottawa, Ontario, Canada May 5, 2021. REUTERS/Blair Gable

Canada's Conservative Party leader Erin O'Toole speaks during Question Period in the House of Commons on Parliament Hill in Ottawa, Ontario, Canada May 5, 2021. REUTERS/Blair Gable

Britain's Chancellor of the Exchequer Rishi Sunak serves chips to the leader of the Welsh Conservatives Andrew RT Davies during a visit to Marine Holiday park in Rhyl, Wales, Britain, May 5, 2021. REUTERS/Phil Noble/Pool

Britain's Chancellor of the Exchequer Rishi Sunak talks with the leader of the Welsh Conservatives Andrew RT Davies and Britain's Secretary of State for Wales Simon Hart during a visit to Marine Holiday park in Rhyl, Wales, Britain, May 5, 2021. REUTERS/Phil Noble/Pool

British Prime Minister Boris Johnson, right, and mayor for West Midlands Andy Street ride bikes during a Conservative party local election visit, in Stourbridge, Britain May 5, 2021. Rui Vieira/Pool via REUTERS

British Prime Minister Boris Johnson rides a bike during a Conservative party local election visit, in Stourbridge, Britain May 5, 2021. Rui Vieira/Pool via REUTERS

British Prime Minister Boris Johnson meets with Jan Pritchard, left, and Maggie Bickett, near the Stourbridge canal in the West Midlands during a Conservative party local election visit, in Stourbridge, Britain May 5, 2021. Rui Vieira/Pool via REUTERS

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), wearing a protective face mask and a helmet, visits a construction site in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), talks to journalists during a visit in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), talks to journalists during a visit in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Britain's Prime Minister Boris Johnson gestures as he campaigns on behalf of Conservative Party candidate Jill Mortimer (unseen) in Hartlepool, north-east England May 3, 2021 ahead of the Hartlepool by-election. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson gestures as he campaigns on behalf of Conservative Party candidate Jill Mortimer (unseen) in Hartlepool, north-east England May 3, 2021 ahead of the Hartlepool by-election. Lindsey Parnaby/Pool via REUTERS

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), wearing a protective face mask and a helmet, visits a construction site with Mayor of Nice Christian Estrosi, in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), wearing a protective face mask and a helmet, visits a construction site with Mayor of Nice Christian Estrosi, in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), wearing a protective face mask and a helmet, visits a construction site in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), talks to journalists during a visit in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), talks to journalists during a visit in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Les Republicains (LR) conservative party member Renaud Muselier, president of the regional assembly and candidate for the upcoming regional elections in the southern Provence-Alpes-Cote d'Azur region (PACA), talks to journalists during a visit in Nice, France, May 3, 2021. REUTERS/Eric Gaillard

Britain's Prime Minister Boris Johnson campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson gestures as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson speaks as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson speaks to a member of the public as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson looks on as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson poses for a selfie with a member of the public as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson poses for a selfie with a member of the public as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS

Britain's Prime Minister Boris Johnson gestures as he campaigns on behalf of Conservative Party candidate Jill Mortimer in Hartlepool, Britain May 3, 2021. Lindsey Parnaby/Pool via REUTERS