![A 'Stay Home' sign in London in late December, as many parts of the UK grapple with Tier 4 Covid-19 restrictions. Cases of the disease have been rising quickly and Prime Minister Boris Johnson is expected to announce further measures](https://s.wsj.net/public/resources/images/FN-AM167_FN_COV_M_20210104082721.jpg)
A third national lockdown is potentially on the horizon, as Prime Minister Boris Johnson confirmed tougher measures will be announced “in due course”.
Primary schools were told to reopen this week despite outcry from teachers’ unions and leading scientists. Almost 80% of England is now operating under the toughest restrictions, known as Tier 4, which bans all households from mixing in most indoor and outdoor settings.