Sir Keir Starmer has backed moves to ramp up the Covid booster jab programme as he warned the NHS is in danger of being “overwhelmed” by the emergence of the new Omicron variant.

The Labour leader said that it was essential to put the national interest first as he urged people to “stick to the rules” and get their top-up injections.

Boris Johnson announced on Sunday that every eligible adult in England was to be offered a third dose of the vaccine by the end of December.

In a televised address in response, Sir Keir said ministers should have acted sooner in the face of the threat from the fast-spreading Omicron strain.

“We may not be certain how dangerous it is but we do know that lives are at risk and again our NHS is at risk of being overwhelmed,” he said.

“If that happens more people will die.

“So we must do everything that we can to protect the NHS.”

Sir Keir said delivering the accelerated booster jab programme would be a “big challenge” but that he was confident the public would rise to meet it.

“Time and time again the British people have risen to the challenge so let’s pull together now and do the right thing once more,” he said.

“At times like this, we must all put the national interest first and play by the rules.

“Of course I understand that sticking to the rules can be inconvenient but stick to the rules we must.

“It would be easy to let the festivities we’ve all been looking forward to, divert us from our national duty.

“Getting jabbed, wearing masks and working from home if we can really will help prevent infections and help prevent the NHS being overwhelmed.”