Prime Minister Boris Johnson has hinted that tougher coronavirus restrictions could be implemented in coming weeks in view of Britain's dire situation.
"It may be we need to do things in the next few weeks that will be tougher in many parts of the country," Johnson told the BBC on Sunday without offering further detail.
"I'm not going to speculate now about what they would be but ... clearly school closures, which we had to do in March is one of those things," Johnson said.
The country's tiered system based on infection levels is "probably about to get tougher" even despite the roll-out of vaccines, the prime minister added.
Opposition leader Keir Starmer said Johnson could no longer wait before imposing a tougher nationwide lockdown.
"It's not good enough for the prime minister to hint at further restrictions at unspecified times and then do nothing," the Labour leader wrote on Twitter.
"He must put national restrictions in place within the next 24 hours," Starmer said, adding that the virus was "out of control".
Britain registered a record number of new infections on Saturday, many of which are attributed to a possibly more contagious virus strain that is particularly rampant in London.
Schools in the capital will remain closed for the time being after the Christmas holidays, though in other parts of the country, primary schools will open on Monday, followed in the weeks after by secondary schools.
"Schools are safe", Johnson said again on Sunday.
"There is no doubt in my mind that schools are safe, and that education is a priority."