SIR KEIR STARMER has urged Boris Johnson to convene an urgent Cobra meeting to review the Christmas relaxation of Covid-19 restrictions, following a sharp rise in cases over the past week. 

In a letter to the Prime Minister today the Labour leader accused ministers of risking a third wave in the new year by allowing unlimited numbers from up to three households to socialise together between December 23 and 27.

Downing Street has so far insisted there are no plans to change the “Christmas bubble” policy, despite increasing concerns.

Sir Keir said that the three-tier system of restrictions imposed in England after the month-long lockdown ended two weeks ago had failed to control transmission of Covid-19, and warned that the “ramifications for our NHS and our economy could be severe.”

It was understandable that people wanted to spend time with their families “after this awful year,” but “the situation has clearly taken a turn for the worse,” the Labour leader said.

His call came after two leading medical journals recommended scrapping the “rash decision” to relax social-distancing measures.

In a rare joint editorial, the British Medical Journal and Health Service Journal warned that the government’s easing of coronavirus restrictions over Christmas would risk a third wave and “many lives.”

“Many will see the lifting of restrictions over Christmas as permission to drop their guard,” they said.

The editorial, by HSJ editor Alastair McLellan and BMJ editor-in-chief Fiona Godlee, also voiced concern over a new strain of Covid-19 that is suspected to spread faster.

They said that the mutated virus has “introduced further potential jeopardy.”

Their warning came after Health Secretary Matt Hancock revealed on Monday that there had been more than 1,000 cases involving the new variant in England, mainly in the south-east.

Mr Hancock went on to announce that London and parts of Essex and Hertfordshire would be put under Tier 3 restrictions from tomorrow (Wednesday).

Chief Secretary to the Treasury Stephen Barclay said on Sky News that all things were kept under review, and urged people to show restraint over Christmas and “do the minimum” if they visit family.

But he rejected the idea that the government was “letting people loose.”