Boris Johnson has called for parents to be "patient" over the ending of bubbles as his own MPs and senior Downing Street officials warned that the situation in schools was worsening by the day.

The Prime Minister addressed the issue for the first time as he moved to quell a growing revolt within the Tory party over healthy children being sent home en masse to self-isolate.

This week, The Telegraph launched a campaign calling on ministers to put children first as the country recovers from its repeated Covid lockdowns, with action to bring an end to the disruption in schools.

On Thursday, Mr Johnson said he understood the "frustration" over whole bubbles being sent home to isolate, adding that officials were awaiting Public Health England’s analysis of a pilot in which children were tested every day for a week after a classmate tested positive. If successful, the model could replace self-isolation for healthy schoolchildren.

"They haven’t concluded yet, so what I want to do is just to be cautious as we go forward to that natural firebreak of the summer holidays when the risk in schools will greatly diminish and just ask people to be a little bit patient," Mr Johnson said.

Campaign for children (Day 3)

But the Prime Minister’s words fell on "stony ground", according to Tories who said his remarks about patience "have gone down very badly on the Conservative MP WhatsApp groups".

There  was a warning from within Downing Street that Mr Johnson needed to act with urgency. A Number 10 source told The Telegraph: "We’re talking about catch-up – but if kids aren’t spending time in school, then how can we begin that programme to replenish what they’ve lost in lockdown?

"We need to get to a position where our children are able to benefit from the contact, the nurture of the classroom. I do think that the catch-up programme is in a sense being put at risk by a lot of this."

The most recent figures show that 385,500 children are off school and isolating because of Covid, the vast majority of whom do not have the virus.

If the figures continue to rise at the rate they have been over the past seven-day period, up to two million children could be forced to stay at home during the final week of the summer term.

Writing in The Telegraph, Ruth Davidson, a former leader of the Scottish Conservatives, urged ministers to implement a "sensible" rule change on bubbles as soon as possible, adding: "It’s not too late to do right by our nation’s children."

Self-isolation exodus from schools

On Thursday night, the Government’s social mobility tsar became the latest voice in Whitehall to call for bubbles to be axed before the end of term.

Steven Cooper, the co-chairman of the Social Mobility Commission, said disadvantaged children were suffering the most and the consequences of them missing school were significant. He added that ending bubbles "can’t wait until September – you have to start that now".

Tim Loughton, a former children’s minister, said there needed to be "absolute urgency" from the Government to scrap bubbles.

"Common sense has been thrown out the window – they just need to get rid of all these bubbles ASAP," he said. "The whole Department for Education operation has lacked a sense of urgency, and the children have been the collateral damage."

Iain Duncan Smith, a former Tory leader, said: "Let’s get rid of bubbles before the end of term. What are we waiting for? This is about schools, which are for the most part the least threatened group in society. I think almost everyone in the Conservative party wants action on this now."

Michael Vaughan, the former England cricket captain, added his support to The Telegraph’s campaign, saying it was "heartbreaking" that healthy children were being forced to isolate.

Writing in The Telegraph, he said: "The policy of sending whole bubbles home because one child tests positive has to end quickly. The ramifications run deeper than just lost school time. Sport is also badly affected by these draconian measures."

Children’s activity by gender

Multiple Tory MPs have said they are being bombarded with letters of concern from constituents whose children have been told to self-isolate multiple times even though they then test negative for Covid.

Some have expressed concern that continued home schooling has placed a financial burden on their household, forcing them to take time off work or scale back businesses they run.

Steve Baker, the deputy chairman of the Covid Recovery Group, said he was "aghast" that Mr Johnson was calling for patience, adding: "The Government should be working immediately to end bubbles and self isolation for children as an absolute priority."

On Thursday, Mr Johnson also warned that "extra precautions" could be in place after July 19, raising concerns that restrictions could remain beyond what is being described as "Freedom Day".

Speaking during a visit to the Nissan plant in Sunderland on Thursday, he told reporters: "I know how impatient people are to get back to total normality, as indeed am I.

"I will be setting in the course of the next few days what Step Four will look like exactly. But I think I’ve said it before – we’ll be wanting to go back to a world that is as close to the status quo, back to life as close to it was before Covid.

"But there may be some things we have to do, extra precautions that we have to take, but I’ll be setting them out."

A government adviser admitted on Thursday that modelling that helped persuade the Prime Minister to delay the June 21 reopening was overly pessimistic and the release should "possibly" have gone ahead on time.

Dr Mike Tildesley, an epidemiologist from Warwick University, said Britain had been in a "much better situation than we thought" when his group released models suggesting third wave deaths could hit 72,000.

It came as NHS bosses called for a change to self-isolation rules for double-vaccinated healthcare workers, with up to a fifth of staff in some parts of the UK off work.

One senior NHS manager said: "The rules around [self-isolation] need a rethink. I’ve got lots of medics who are saying: ‘I’m double jabbed, I’ve done a flow test, I’m negative, can I come back to work?’.

"Covid-positive patients are nowhere near as sick [as before] but we’ve also got like, 130, 140, registered nurses off, isolating, and this is a big issue."

Leading figures in the hospitality sector were also demanding a "test and release" scheme to prevent a staffing crisis caused by the NHS Test and Trace app.

Hugh Osmond, a former boss of Pizza Express who has founded the Various Eateries group, told BBC Radio 4’s World at One: "Like schools, what we are finding is the vast majority of people that get pinged by the app do not at any stage test positive either on lateral flow tests or PCRs."