A Government adviser has warned that daily coronavirus cases need to fall dramatically before Boris Johnson can consider easing lockdown measures.

It is “not sensible” for the Government to draw up a road map out of lockdown before local transmission is under control, said Sir Jeremy Farrar, director of the Wellcome Trust and a member of the Scientific Advisory Group for Emergencies (Sage).

The Government’s daily figures on Thursday showed a further 13,494 lab-confirmed cases of coronavirus in the UK.

The most recently published Office for National Statistics estimates suggest around one in 65 people in private households in England had Covid-19 between January 24 and 30, the equivalent of 846,900 people.

Transmission is still incredibly high in the UK. If transmission were still at this level and we were not in lockdown, we would be going into lockdown

Sir Jeremy said the ONS data would need to fall below 50,000, from its current level of around 750,000, before the Government should think about lifting restrictions, the Wellcome Trust said.

Daily case numbers would need to fall to fewer than 1,000 and preferably under 500 a day.

Downing Street said ministers “will look at the data in the round” when it comes to decisions on easing restrictions.

The Prime Minister is expected to set out his road map for easing the lockdown on February 22.

But Sir Jeremy said it “doesn’t make any sense” to set out plans to ease restrictions with arbitrary dates in March or April.

“Transmission is still incredibly high in the UK. If transmission were still at this level and we were not in lockdown, we would be going into lockdown,” he said.

“There are 750,000 people today in the UK infected, there’s still huge pressure on the NHS and on critical care in this country.

“We’ve made enormous progress – the UK deserves great credit for the science behind the vaccines and the rollout, (with) 13 million people vaccinated in this country.

“But the transmission rate is incredibly high still and we’ve got to get it lower, we’ve got to get it – in my view – into the single thousands before we can possibly think about lifting restrictions.”

He told BBC Radio 4’s Today programme: “I appreciate that businesses have to plan and everything else, but the data has to drive us, and in 2020 we lifted restrictions too quickly when the data would not really have allowed that and, frankly, as a result the transmission went back up in this country.”

Sir Jeremy said new coronavirus variants are a “massive warning” about the risks of lifting restrictions before the vaccine programme has been fully rolled out.

He warned that stricter new border controls will have little impact while community transmission is so high.

Sir Jeremy added: “Border controls can work if transmission is very low, if they are very comprehensive and you’re willing to put them in place for a very long time.

“They buy you time, but they don’t reduce transmission when your transmission is already very high.”

Sir Jeremy believes that if the vaccination rollout is successful and robust public health measures such as contact tracing and isolating remain in place then transmission can be kept low.

The Prime Minister’s official spokesman said: “We want to see infection rates continue to fall across the UK, not least so that will ease the pressure on the NHS and ultimately lead to fewer people sadly dying.

“We will look at the data in the round and we will use that to inform the road map.”