Boris Johnson has faced further pressure from his own Conservative MPs over the extension of lockdown restrictions until 19 July.
Tory backbencher Philip Davies called on the PM to listen to his "Conservative instincts" and trust the country's vaccination programme instead of listening to "communist scientists".
Meanwhile, fellow Conservative MP William Wragg asked for an assurance that the easing of lockdown measures will not be delayed once more beyond the new 19 July date.
It comes after the PM announced on Monday that a four-week delay to the relaxation of restrictions was necessary to allow more people in England to receive a second coronavirus vaccine and to curtail the spread of the Delta variant.
New data suggests the Delta variant, formerly known as the Indian variant, is associated with a 64% increased risk of household transmission.
Some Conservative MPs have criticised the prime minister's deviation from the government's roadmap out of lockdown and urged restrictions to be eased immediately.
There will be a Commons vote on the matter where MPs will have a chance to have their say on the extension of coronavirus laws.
Speaking at PMQs on Wednesday, Mr Johnson reiterated he believes the four-week delay will save "many thousands more lives" and that restrictions will not be in place "forever".
But MP for Shipley Mr Davies raised concerns that some members of independent scientific advisory groups would like restrictions to be in place "forever".
"One of the reasons for the popularity of the prime minister is that he has always been on the side of the public rather than on the side of the establishment," Mr Davies told the Commons.
"Given that overall deaths in the UK over the last 13 weeks are 8.873 below the five-year average - which includes the time the Indian variant has been around - can [Mr Johnson] explain why, instead of trusting his world-leading vaccine programme, the common sense of the British people and his Conservative instincts of individual freedom and individual responsibility, he instead decides to trust people like Professor Susan Michie at Sage - a long standing member of the Communist Party, who last week let the cat out of the bag and said she wanted some COVID restrictions to last forever?"
Mr Johnson replied: "Nobody, least of all I or [Mr Davies] want to see COVID restrictions last forever, nor do I think that they are going to last for ever.
"Because, as I made clear earlier this week, I think we can have a high degree confidence that our vaccination programme will work and I think we need to give it a little bit more time - as I have explained - to save many thousands more lives by vaccinating millions more people."
Fellow Conservative William Wragg urged the PM to "convince" the public that their freedoms will be restored on 19 July.
"When can we expect the coordinated chorus of Sage members recommencing their media appearances to suppress morale?" the MP for Hazel Grove said.
"And does [Mr Johnson] fear having to give another press conference at which he again postpones the return of our freedoms?
"We are rightly told that we need to learn to live with COVID, so what can the prime minister say to the country to convince us of that reality?"
Mr Johnson replied: "Academic and scientific freedom are a valuable part of our country and I also note that my scientific colleagues would echo my sentiments that we need to learn to live with COVID."
The proposed extension will be reviewed to see if action can be taken two weeks sooner on Monday 5 July.
However, Mr Johnson did announce some changes, scrapping the 30-person limit on weddings from 21 June as planned and removing the requirement for care home residents to quarantine for 14 days after day trips.