Tory leadership: Theresa May signals she may oppose Boris Johnson or Jeremy Hunt after she steps down as PM

Outgoing prime minister declines to back successor's EU withdrawal plan in all circumstances

Theresa May has sent her successor as prime minister a signal that he cannot expect her automatic support on Brexit after she steps down.

The PM declined to commit herself to backing her successor’s EU withdrawal plan in all circumstances, including a no-deal outcome.

And she said the new PM - either Boris Johnson or Jeremy Hunt - must secure MPs’ backing for the path he proposes and should not shut down parliament to stop them from voting.

Ms May, who failed three times to win MPs’ support for her own EU withdrawal agreement, insisted that Brexit must be delivered “in a way which is good for the British people”.

And she cast doubt on the leadership rivals’ claims to be able to secure a better deal with changes to the controversial Irish backstop.

Asked if this was a realistic scenario, she pointedly replied: “The EU has made its position clear, as you known, in the various Council minutes that have come out.”

Senior EU officials have repeatedly stated that they will not reopen the withdrawal agreement reached with Ms May last November.

The outgoing PM has previously voted against departure from the EU without a withdrawal agreement, something which neither of the rivals to succeed her have ruled out.

Mr Johnson has adopted a “do or die” strategy, promising to take the UK out of the EU by 31 October with or without a deal.

Mr Hunt has said he is ready to extend negotiations beyond the Halloween deadline, and would go for no-deal “with a heavy heart” only if the sole alternative was halting Brexit.

Asked by The Independent whether she could commit herself now to supporting the outcome offered by her successor, even if this meant no-deal, she indicated this was not something she was prepared to do.

“What you’re saying to me is ‘Will you now say that whatever happens in the future, you’re going to agree with it?’” she said.

“Look, I think it’s important for us to deliver Brexit in a way that is good for the British people. It will be up to my successor to take this forward, to find the majority in parliament that I was not able to find on this issue and to deliver the decision of the British people in 2016.”

Ms May signalled her opposition to any move by her successor to stop MPs from blocking no-deal by asking the Queen to shut down parliament in a process known as “prorogation”.

Asked if this tactic, which was not ruled out by Mr Johnson in a digital hustings on Wednesday, was acceptable, Ms May said: “What I hope and expect is that my successor will be able to put before parliament proposals that will enable us to deliver for the British people in a way which is good for the United Kingdom.”

But she indicated that she was not prepared to take the step being contemplated by some Tories of voting no-confidence in their own party leader to block a no-deal outcome.

Asked if she could rule out ever voting in this way, she said: “As far as I’m concerned, I believe that there should be a Conservative government in the United Kingdom, because a Conservative government is better for the people of the United Kingdom.”

Ms May insisted that the UK’s prospects after Brexit were “good”.

“I’m optimistic about the future for the UK,” she said.

“I think we’ve got a really bright future. We’ve got to get over the delivery of Brexit, actually do that for people.

“Once we’ve done that I think there are real opportunities for the UK. We are a world-leading country, so in many areas such as climate change and others, I think there’s a really bright future for us.”