Cabinet ministers have been accused of attempting to sabotage Brexit as the Tory leadership race hots up.
Esther McVey claimed some of her former Cabinet colleagues were seeking to “dismantle” Brexit as she set out her stall to replace Theresa May.
The former work and pensions secretary said the next leader of the Conservative Party must be somebody who “believes in Brexit” and has the “passion” to drive it forwards.
She said it was “essential” that Britain leaves the EU by the end of October, as she launched a political group aimed at winning over working-class voters to the Tories.
The comments came as digital minister Margot James signalled that it would be difficult for a leadership candidate advocating a no-deal Brexit to get the backing of a new centre-right bloc of Tory MPs called One Nation.
Ms McVey told the Press Association the Prime Minister should be given a “dignified and graceful” departure, but if she attempted to cling on to power “the Cabinet should now step up and say what needs, maybe, to be said”.
Asked whether the Cabinet had done enough so far to resolve the crisis, Ms McVey said: “What is most important is that we deliver on Brexit.
“What you see, maybe in Cabinet, is they’re not wanting anything to happen, they are wanting things to stay in place so they can dismantle Brexit and get Remain through a back door.
“If that is what the Cabinet is doing, then shame on them.”
Ms McVey, who quit over Brexit in November, told the Blue Collar Conservatism event in Parliament that it is “not an easy time” to be a Tory activist.
“Our failure to deliver Brexit has left many feeling demoralised, with no obvious light at the end of the tunnel, and most of us know that ahead of us is still a bumpy ride,” she said.
The staunchly Leave-backing MP, who resigned from the Cabinet in November over the Prime Minister’s deal with Brussels, told the audience of parliamentarians and journalists that the next Tory leader “has to be a Brexiteer” who “believes in Brexit, delivers on our manifesto and even the manifesto of Labour”.
“It is key that we’ve got to get this delivered so we can get on to the domestic issues that affect so many people’s lives,” she said.
Asked if that included the likes of Jeremy Hunt, who supported Remain in the referendum but has since adopted an increasingly Eurosceptic position, Ms McVey said: “I said it has to be a Brexiteer who believes in Brexit.
“Whatever they voted they can tell you, but it has to be somebody who believes, who has got the passion to drive it forward.”
Ms McVey also said there should be “no more backsliding” regarding the UK’s exit, even if it means leaving without a deal on October 31.
She called for the amount spent on international aid to be returned to Labour levels in 2010 in a bid to win over working-class voters – with money shifted to support police and education.
“By doing this, we will be doing more than just making up for shortfalls here and there – we will be providing transformative funds which communities will feel,” Ms McVey said.
She is the latest MP to set out her stall in the race to succeed Mrs May.
Earlier, Health Secretary Matt Hancock refused to rule out a bid for the job, saying he had a “strong view about the sort of leader we need”.
He said the leader should put the Tories “four-square in the centre ground”, a view that will be echoed by big hitters at a meeting of the One Nation group of Tories in Parliament on Monday night.
Former foreign secretary Boris Johnson has already confirmed he will stand in the race to replace Mrs May, which is due to officially begin within weeks.
Another potential contender, Home Secretary Sajid Javid, said “there won’t be a shortage of candidates” for the job but “whether I will be one of those, you’ll just have to wait and see”.
The Prime Minister will set out the timetable for her exit and the leadership contest to succeed her after a crunch vote on the legislation for her Brexit deal in early June.
Defeat for the Withdrawal Agreement Bill, which is due in the Commons in the week beginning June 3, would hasten her exit from Number 10.
Around 25 Tory MPs attended a meeting in Westminster which outlined the One Nation group’s ideas, including rejecting “narrow nationalism”, supporting a “strong society” and backing public services.
Asked if One Nation could back a Tory leadership contender who advocated a no-deal Brexit, Ms James said: “I think it would be difficult for a candidate who would let the country leave without a deal to subscribe to quite a lot of those values and the policies that flow from them.
“I don’t think many candidates are going to stand up and say, ‘I think the country should leave without a deal’. No.
“But there are candidates who will go out of their way to make sure the country doesn’t leave without a deal and that is what we need to ensure we get out of this leadership contest.”
Addressing the One Nation meeting, Work and Pensions Secretary Amber Rudd said: “The Conservative Party is entering a new phase.
“And we here in this room are determined to shape that phase.”
Ms Rudd added: “And sometimes our voices aren’t heard quite as vocally as they should be.
“And part of the launch today is to say we are going to be stepping up, making ourselves heard because we are proud and honest and strong about what we believe in.
“And we believe that this time, more than ever, we need to shape the changing Conservative Party.”
Chancellor Philip Hammond will use a speech to the CBI on Tuesday to warn against “populism” and stress that any Brexit position would need to command a majority in Parliament.
Sources said he would also stress the need for “fiscal discipline” and show how “free trade and market economics can deliver solutions to the issues which are driving voter angst”.