Foreign Secretary Dominic Raab said the Government will not announce whether the coronavirus lockdown should be eased on Monday.
Boris Johnson announced restrictions to limit the spread of Covid-19 two weeks ago, and the prime minister said he would review the measures after three weeks.
However Mr Raab, deputising for Mr Johnson as he is treated in intensive care for coronavirus, said at the daily press briefing on Tuesday that no decision would be made on Monday, April 13.
Downing Street confirmed the review would not go ahead on the scheduled date and said it would instead take place after the three-week mark.
The move came as the chief scientific adviser suggested the peak of the outbreak could be near, but he stressed the evidence would not be available for at least another week.
Mr Raab was pressed on whether the review would take place as scheduled at the Downing Street briefing.
He said: “The critical thing is to take evidence-based decisions and so we’ve said that we will take any review once we’ve got the evidence that the measures are working.
“And having the kind of impact taking us past the peak which means that they can be responsibly done. We’re not at that stage yet.”
England’s chief medical officer Professor Chris Whitty said the peak – where the virus is at its most widespread – must be in the past before decisions can be made.
“It’s really important that we get to the point that we’re all confident that we’re beyond the peak and then at that point start making it clear what combination of things and over what period of time seems a sensible combination to take us through,” he said.
The Government’s chief scientific officer, Sir Patrick Vallance, said it is possible the nation is seeing the beginning of the steadying of the coronavirus rate.
“We won’t know that for sure for a week or so,” he added.
“There hasn’t been the accelerated take-off and again it’s possible that we’re beginning to see the start of a change where we might see numbers flattening off,” he said.
“It does begin to suggest that things might be moving in the right direction in terms of numbers and it’s important that we carry on with the measures that we have got in place in order to make sure that this does go in the right direction.”
Mr Johnson announced the unprecedented measures to ease the burden on the NHS by slowing the disease’s spread in a televised statement on March 23.
He ordered the closure of all non-essential shops, banned all travel that is not absolutely necessary and permitted only one form of exercise per day.
“And I can assure you that we will keep these restrictions under constant review. We will look again in three weeks, and relax them if the evidence shows we are able to,” he said.
After being taken to hospital on Sunday while suffering persistent symptoms of the virus, Mr Johnson was moved into intensive care on Monday night.
Coronavirus: Everything you need to know