Prime Minister Boris Johnson, whose government is again under fire after the resignation of his health minister Matt Hancock for breaking the restrictions by kissing his aide, had hoped to unlock Britain's economy last week.

But with coronavirus cases rising, driven largely by the more transmissible Delta variant, the government postponed the date until July 19 amid criticism from many businesses which want lockdown to end to try to recoup their losses.

"With every day that goes by it's clearer to me and all our scientific advisers that we're very likely to be in a position on July 19 to say that really is the terminus and we can go back to life as it was before COVID as far as possible," Johnson told reporters.

Hancock's replacement, Sajid Javid, confirmed the decision in parliament, saying he had spent his first day in the job studying the data to see if the next stage of easing restrictions, called step four, could go ahead any earlier.

"Whilst we decided not to bring forward step four, we see no reason to go beyond the 19th of July," he told parliament, urging the public to stick to the restrictions for now.

"July 19th remains our target date. The prime minister has called it our terminus date. For me, the 19th of July is not only the end of the line but the start of a exciting new journey for our country."

VACCINATIONS

Britain, which has one of the highest official death tolls from COVID, is seeing case numbers rise again, with daily increases topping 10,000 in recent days. But officials say a mass vaccination campaign is weakening the link between cases and deaths.

Some officials fear the public may start breaking the rules after the Sun newspaper published images of Hancock kissing and embracing an aide in his office at a time when it was against the rules for people to hug anyone outside their household.

Johnson initially said on Friday that he considered the matter closed after Hancock publicly apologised, but on Saturday accepted his resignation, although he described feeling sorry to have to receive the resignation letter.

"I read the story on Friday and we've got a new health secretary in post on Saturday - and I think that's about the right pace to proceed in a pandemic," he said.