Cabinet ministers are facing a hostile reception from the Tory party’s grassroots when they return to their constituencies this weekend after waving through manifesto-busting tax rises in Parliament.

       One constituency chairman told The Telegraph that he was “greatly saddened” that the liberation of Britons from the state under Margaret Thatcher in the 1980s was now being “rolled back by a Conservative Prime Minister”.

       Boris Johnson is experiencing a backlash over the tax increase, with activists, donors and former party chairmen all expressing their dismay about the 1.25 percentage point rise in National Insurance to pay for the NHS and social care.

       The Prime Minister has also faced questions about whether his Conservative Party remained committed to low taxes after he raised the tax burden to the highest level in 70 years.

       A sample of constituencies represented by at least four members of the Cabinet - Michael Gove, the Cabinet Office Minister, Grant Shapps, the Transport Secretary, Therese Coffey, the Work and Pensions Secretary, and Alok Sharma, the COP26 president - uncovered concern among local party volunteers.

       Richard Robinson, chairman of the Conservative Association in the Surrey Heath constituency of Mr Gove, said: “Some Conservatives are going to be very, very upset about this, so I hope the country can understand why they’ve done it.

       “There is a problem and it needs to be solved but I do have some questions about this.”

       Stephen Boulton, a Conservative councillor and a senior official in Mr Shapps’ Welwyn Hatfield constituency, said “A lot of older working people are now going to have to start paying more tax and that’s not something they’ve ever been expected to do before,” he told The Telegraph. “And putting up National Insurance during a pandemic just isn’t very nice.”

       Sir Michael Bunbury, local party president in the Suffolk Coastal constituency of Ms Coffey, said: “A Conservative government raising taxes is very, very hard to take.

       “A pandemic wasn’t written into our manifesto, but National Insurance is not a good tax because it’s a tax on jobs.

       “The Prime Minister is really stressing true-blue conservatives with policies that, as a columnist, he would have ridiculed. I think we shall lose members, there will be some pretty upset people.

       “A lot of my generation felt that the country was liberated post-1979 from its destination to go down the plughole. I am greatly saddened that some of that liberation, characterised by Mrs Thatcher, is being rolled back by a Conservative Prime Minister.”

       Tom Marino, chairman of the Reading West Conservatives in Mr Sharma’s constituency, said: “As a Conservative I am against raising taxes and I would hope that the party would not have made this decision in any other circumstances.

       “I don’t think intergenerational warfare benefits anybody, but a lot of people have been in touch to say that it’s younger people who are working and earning less who will be paying the price for this.”

       The Prime Minister has attempted to fight off the criticism, telling the 1922 committee of backbench Tory MPs this week: “We should never forget after all we’ve been through that we are the party of free enterprise, the private sector and low taxation.”

       But Mr Johnson is now facing a stormy party conference next month with activists starting to rip up their membership cards.

       John Strafford, the chairman of the Campaign for Conservative Democracy, is organising a fringe event at the party conference, which begins in Manchester on October 3, titled “Time for the Conservative Party to be Conservative”.

       Amanda Milling, co-chairman of the Conservative Party, is now likely to face questions about the increase at the annual meeting of the Conservative party convention, which consists of local party chairman, on the eve of the conference.

       Mr Strafford, whose organisation represents grassroots Tories, said: “The Conservative party has lost its way. It is no longer promoting Conservative values.”

       Some Cabinet ministers are privately deeply concerned about the proposals. One told The Telegraph that they feared the plans were “the death knell of Conservatism”.