The scientist running one of the United Kingdom's biggest COVID-19 study programs says Prime Minister Boris Johnson's announcement that he is bringing forward the time when people who have tested positive will no longer be required to self-isolate is "totally wrong" and a decision made on political rather than scientific grounds.

Tim Spector, who is head of the Zoe COVID study unit at King's College London, told Times Radio that the government's desire to send a message to the world that Britain is the first country to be moving out of the pandemic was "act of irresponsibility".

Official UK government statistics for Feb 12 showed 167 deaths within 28 days of a positive test, with a total of 159,518 deaths within 28 days of a positive test for the whole of the pandemic.

There are still around 200,00 cases being reported daily, but in Parliament last week, Johnson, whose premiership has been marred in controversy for weeks over claims that he and his office staff broke lockdown regulations, announced a change to what he called the government's living with COVID strategy.

"It is my expectation that we will be able to end the last domestic restrictions - including the legal requirement to self-isolate if you test positive - a full month early," he said, which would mean at the end of February.

This drew a mixed response, with many people questioning why previously high-profile figures such as Chris Whitty, the government's chief medical advisor, have not been seen for weeks.

"This is more a political type of statement rather than a scientific one," said Spector. "I think we have to really look at this in the context, both of politics and science, and also what's happening, because there is some rationale to this and other countries are doing things similar, but it's clearly a race for the government to say that Britain is first, Britain is the first to come out of this, Britain has conquered Omicron, our booster program is world beating ...."

He called the data the government was using "highly disputed "and said figures from the Office for National Statistics showed the country was still close to where it had been at the turn of the year.

"It's definitely not over - your risk of getting it is huge - and to suddenly give the wrong message, by saying: 'We're getting rid of all restrictions, if you've got an infection don't bother isolating', which is sort of implied but not said, that is totally wrong," he added.

Spector's opinions were echoed by Penny Toff, chair of the British Medical Association's public health medicine committee.

"We must question on what scientific basis this decision is being made and the government needs to show the evidence for its proposals," she said.

"Any sharp rebound of case rates and hospitalizations as a result of this decision, could have a serious impact for the health service as would greater staff absence from illness - adding to the workforce shortage and further delaying providing non-COVID healthcare."