Esther McVey has claimed some of her former Cabinet colleagues were seeking to “dismantle” Brexit as she set out her stall to replace Theresa May as the Tory leadership race hots up.

The former work and pensions secretary who represented Wirral West from 2010 to 2015 said the next leader of the Conservative Party must be somebody who “believes in Brexit” and has the “passion” to drive it forwards.

Wirral Globe:

Former Cabinet minister Esther McVey (Stefan Rousseau/PA)

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.

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.