It came after ministers made changes critics believe “disadvantage the less well-off”. Although the rebels failed, the backlash is set to spread to the Lords where former ministers will attempt to force a climbdown by the Government.

In an intervention that will be seen as reflecting wider Tory concerns over tax rises, Lord Frost said on Monday: “I can’t share the views of those who think we can treat the private sector as just a convenient way of keeping the public sector running.

“It isn’t just a source of taxes. Nor is it a bunch of people who will inevitably do bad things unless the Government keeps a very close eye on them. We can’t carry on as we were before and if, after Brexit, all we do is import the European social model, we will not succeed.”

There has been widespread disquiet among Tory MPs in recent weeks as the botched handling of the Owen Paterson lobbying row saw Labour pull ahead in opinion polls.

Cabinet ministers are being sent to campaign in Old Bexley and Sidcup ahead of next week’s by-election – a sign of the precaution being taken over what should be an easy hold for the Tories.

Under Mr Johnson, the tax burden has risen to its highest level in 70 years despite both the Prime Minister and Rishi Sunak, the Chancellor, insisting that they are low-tax Tories at heart.

Speaking at the Centre for Policy Studies conference, Lord Frost said: “The formula for success as a country is well known. Low taxes – I agree with the Chancellor, as he said in his Budget speech, our goal must be to reduce taxes –  light-touch and proportionate regulation, whatever our policy objectives.”

Calling for debate on government decisions, Lord Frost, one of three ministers who spoke out in Cabinet against the National Insurance rise earlier this year, said: “To make the best decisions, we need the fullest and freest possible debate.

“I believe that free debate is a good thing. It forces everyone to test their arguments, and I strongly believe it means the best ideas win.”

Earlier on Monday, Mr Johnson made a speech outlining his pro-business vision to the CBI – but the message was overshadowed by perceived blunders in his delivery. In the address, he invoked Peppa Pig as proof of the power of the free market and jokingly likened himself to Moses as he argued the case for a green revolution.

On social care, Esther McVey, the former pensions secretary, and Dan Poulter, a former health minister, were among 18 Tories who on Monday night rebelled against an amendment to the Health and Care Bill, which will stop means-tested support counting towards the new £86,000 cap on costs.

It means more people in England will pay higher care costs.

Mark Harper, the former chief whip, said: “It potentially disadvantages the less well-off and those of working age with life-long conditions.”

A further 69 Tories recorded no vote, of which a proportion will have had permission to miss the division, but others will have chosen to abstain.

Amid a fierce whipping operation, some Tories reported they had chosen to abstain rather than rebel, in the expectation the House of Lords would send it back to the Commons later for reconsideration. Lord Lansley, the Former Conservative health secretary, and Baroness Altmann, the former pensions minister, said they would seek to amend the legislation when it arrives in the upper chamber.

The Prime Minister’s allies in Government were on Monday night waving away criticisms of him, arguing that they were politically motivated attacks.

But one adviser to a Cabinet minister told The Telegraph: “There is just a lot of stress. The PM’s obviously very, very unhappy. No PM wants to be in a rough patch. It is not out of the ordinary. I would imagine he’s not enjoying it.”

Sir Keir Starmer, the Labour leader, piled further pressure on Mr Johnson by touting his plans to abolish business rates and doubling down on opposition to the Government’s National Insurance rise.

He told the CBI: “The reason we opposed the Government’s tax rises now is because business said to us that ‘as we come out of the pandemic and we are trying to get back on our feet, the last thing we need now is to be held back by tax’.”