Britain's Deputy Chief Medical Officer for England Jenny Harries holds a virtual news conference at 10 Downing Street, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, March 8, 2021. REUTERS/Hannah Mckay/Pool

Britain's Prime Minister Boris Johnson and Deputy Chief Medical Officer for England Jenny Harries hold a virtual news conference at 10 Downing Street, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, March 8, 2021. REUTERS/Hannah Mckay/Pool

Britain's Prime Minister Boris Johnson and Deputy Chief Medical Officer for England Jenny Harries hold a virtual news conference at 10 Downing Street, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, March 8, 2021. REUTERS/Hannah Mckay/Pool

Britain's Prime Minister Boris Johnson holds a virtual news conference at 10 Downing Street, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, March 8, 2021. REUTERS/Hannah Mckay/Pool

Britain's Prime Minister Boris Johnson holds a virtual news conference at 10 Downing Street, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, March 8, 2021. REUTERS/Hannah Mckay/Pool

British Labour Party leader Keir Starmer and Shadow Education Secretary Kate Green wear masks during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer meets pupils during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer meets pupils during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer meets pupils during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer meets pupils during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer meets pupils during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer has his temperature checked during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer wears a mask during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer wears a mask during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer wears a mask during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

British Labour Party leader Keir Starmer and Shadow Education Secretary Kate Green wear masks during a visit to Sydney Russell School, where teachers and students are returning to the classroom after coronavirus disease (COVID-19) lockdown, in Dagenham, London, Britain March 8, 2021. Stefan Rousseau/Pool via REUTERS

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe is interviewed as he protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe is interviewed as he protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe is interviewed as he protest outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Demonstrators, wearing masks to prevent the spread COVID-19, take part a rally to mark International Women's Day in Ankara, Turkey March 8, 2021. REUTERS/Cagla Gurdogan

Demonstrators, wearing masks to prevent the spread COVID-19, take part a rally to mark International Women's Day in Ankara, Turkey March 8, 2021. REUTERS/Cagla Gurdogan

Women wearing traditional dresses sit next to the security barriers during a rally to mark International Women's Day in Diyarbakir, Turkey March 8, 2021. REUTERS/Sertac Kayar

Women wearing traditional dresses dance during a rally to mark International Women's Day in Diyarbakir, Turkey March 8, 2021. REUTERS/Sertac Kayar

A demonstrator carrying a child takes part in a rally to mark International Women's Day in Diyarbakir, Turkey March 8, 2021. REUTERS/Sertac Kayar

A woman wears a face mask as she walks past a closed retail unit amid the outbreak of the coronavirus disease (COVID-19) in Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

A deliveroo delivery driver is seen in the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

A deliveroo delivery driver is seen in the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

A deliveroo delivery driver cycles through the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

A deliveroo delivery drivers waits to pick up an order outside a coffee shop in the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

A deliveroo delivery driver cycles through the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

Deliveroo delivery drivers cycle through the centre of Manchester, Britain, March 8, 2021. REUTERS/Phil Noble

Students wear masks during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Students write during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Students fold paper during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe, protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Students listen to a teacher during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Students listen to a teacher during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Students listen to a teacher during a lesson at Heath Mount school as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Ethnic Uighur demonstrators wave East Turkestan flags during a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

An Ethnic Uighur demonstrator wearing a protective face mask to prevent the spread of the coronavirus disease (COVID-19), takes part in a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

Ethnic Uighur demonstrators wave East Turkestan flags during a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

Ethnic Uighur demonstrators wave East Turkestan flags during a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

Ethnic Uighur demonstrators holding East Turkestan flags take part in a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

An Ethnic Uighur demonstrator holding a placard reads that: "Rape is crime of humanity" takes part in a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

Ethnic Uighur demonstrators wave East Turkestan flags during a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

An Ethnic Uighur demonstrator holding a placard reads that: "Rape is crime of humanity" takes part in a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

An Ethnic Uighur demonstrator holding a placard reads that: "Rape is crime of humanity" takes part in a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

A teacher at Heath Mount school holds a lesson outside as schools reopen in England, amid the coronavirus disease (COVID-19) pandemic, in Watton at Stone, Hertfordshire, Britain March 8, 2021. REUTERS/Andrew Couldridge

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe, speaks to the media as he protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Gabriella Ratcliffe, daughter of British-Iranian aid worker Nazanin Zaghari-Ratcliffe, protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Richard Ratcliffe, husband of British-Iranian aid worker Nazanin Zaghari-Ratcliffe, and their daughter Gabriella protest outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Gabriella Ratcliffe, daughter of British-Iranian aid worker Nazanin Zaghari-Ratcliffe, protests outside the Iranian Embassy in London, Britain March 8, 2021. REUTERS/Andrew Boyers

Ethnic Uighur demonstrators wave East Turkestan flags during a gathering on the occasion of International Women's Day to protest China's treatment of Uighurs, in Istanbul, Turkey March 8, 2021. REUTERS/Murad Sezer

A year 7 student takes a COVID-19 lateral flow test on the first day back at school, as the coronavirus disease (COVID-19) lockdown begins to ease at Harris Academy Sutton, south London, Britain, March 8, 2021. REUTERS/Toby Melville

A lateral test is seen as Nicky Clough visits her mother Pam Harrison (both not pictured) in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

A sign hangs on the door as Nicky Clough (not pictured) visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay

Nicky Clough visits her mother Pam Harrison in her bedroom at Alexander House Care Home for the first time since the coronavirus disease (COVID-19) lockdown restrictions begin to ease, in London, Britain March 8, 2021. REUTERS/Hannah Mckay