Esther McVey has said she would run to succeed Theresa May as Tory leader and prime minister if she had enough support.
“If people felt I could and they wanted to back me I would,” the former work and pensions secretary said on Sunday.
McVey quit the government in protest at May’s Brexit deal. But she has now said she will vote for it when it is put to another vote.
It has been suggested that more Tory MPs would be prepared to swing behind the deal if May promises to resign as party leader shortly after securing the agreement.
Speaking to Sky News’ Ridge on Sunday programme, McVey said May’s hold on power was now “very dubious”.
“She has got to look at the fact – when collective responsibility collapses like that, who is the voice of government?” she said.
“The government should only have one voice so the country knows what we stand for, so the world knows what we stand for.”
McVey said Tory MPs had said she had been asked to run for leader but would wait to see “if people mean it”.
The Brexiteer added: “If there were enough people who supported me, if it seemed there was a reasonable chance, I would.”
MPs are due to vote for a third time on May’s Brexit deal this week. But Chancellor Philip Hammond said this morning the planned vote would be pulled if the government thought it would lose.