British Secretary of State for Work and Pensions Amber Rudd | Peter Summers/Getty Images Hardened Brexit position will ‘collide with reality,’ says UK minister Amber Rudd predicts that the new Tory leader will have a ‘window’ to resolve Brexit.

LONDON — The hardening of the positions of Tory leadership candidates Jeremy Hunt and Boris Johnson on Brexit will “collide with the reality,” Amber Rudd said Tuesday.

Speaking at POLITICO’s Playbook Live event in London, the U.K. work and pensions secretary said she had been surprised by the candidates’ apparent unwillingness to rule out any compromise on the controversial Northern Ireland backstop — the mechanism negotiated as part of the Withdrawal Agreement to avoid the need for a hard border.

At their final head-to-head debate on Monday evening, both candidates declared the backstop “dead” and rejected the idea of a hypothetical five-year time limit (even though such a compromise is not on offer from the EU).

Rudd, a key figure in the Remain campaign who is backing Hunt to be the next prime minister, said: “I was surprised by what they both said and I think their views will collide with the reality when whichever one wins starts negotiating and starts dealing with parliament, which may be more difficult than they think to engage with."

But the Cabinet minister said she believes there would be a “window” of opportunity for the new prime minister to make progress on the Brexit impasse. “I do think that a new prime minister will get a hearing. They will get a hearing from parliament and a hearing from the EU,” she said.

Rudd recently dropped her opposition to a no-deal Brexit to give the new prime minister “leverage” in negotiations with Brussels. She had previously worked with Cabinet colleagues to prevent it and predicted that MPs would in any case find a way to block it.

"I do know that we have an activist speaker, we have a lot of people who are very committed to finding a way and there is legislation and procedures evolving all the time," she said.

Rudd said she had spoken to her natural allies around the Cabinet table before she changed her position and a lot of them had been "very supportive."

"It is about compromise and I think it was the right thing to do. I do feel circumstances had changed," she said.

Rudd also warned any new Tory leader against doing a deal with Nigel Farage's Brexit Party, urging the candidates to stick to their pledge at a hustings event in June organized by the "One Nation" group of moderate Tory MPs.

Some Brexiteers have warned that Johnson would be left with no choice but to form a pact if MPs intent on stopping a no-deal Brexit force a general election.

But Rudd said: "Both the final two candidates ruled it out [at the hustings] and so I hope they will stick to that ... I think a deal with Nigel Farage would be a mistake. The Conservative Party is at its best when it is at its center, liberal, conservative place," she said.

In the hourlong discussion with London Playbook editor Jack Blanchard, Rudd — who is one of only five women to have held one of the four main offices of state, having served as home secretary from 2016 to 2018 — also revealed that she had not always aspired to be an MP, but joked that she thought her career would be modeled on the fictional adventuring archaeologist Lara Croft.

"I had [a] sort of Lara Croft image of myself once, that is true, that is very embarrassing," she said.

"I have always wanted to be involved in government of some sort, but I didn't think I was going to be a member of parliament. I thought maybe an ambassador or something like that would be good."