European Commission president Jean-Claude Juncker has issued a fresh warning to the Tory leadership contenders that they will not be able to renegotiate Theresa May’s Brexit deal.
Mr Juncker said that whoever takes over at No 10 will have to respect the agreement between the UK Government and the EU.
His comments will be seen as a setback to those contenders – including Jeremy Hunt, Michael Gove and Matt Hancock – who have put a strong emphasis on securing a fresh deal with the EU.
Mr Juncker said some “clarifications” may be possible in the Political Declaration, which sets out the basis for negotiations on the UK’s future relationship with the EU.
However he was adamant the Withdrawal Agreement – which includes the controversial Northern Ireland backstop as well as Britain’s £39 billion “divorce” settlement – could not be reopened.
“This is not a treaty between Theresa May and Juncker. This a treaty between the United Kingdom and the European Union,” he said in an interview with the Politico website.
“It has to be respected. It has to be respected by whomsoever will be the next British prime minister.
“There will be no renegotiations as far as the content of the Withdrawal Agreement is concerned.
“We can have some clarifications – precisions, additions – to the Political Declaration concerning the future of our organisations. The Withdrawal Agreement will not be renegotiated.”
His intervention came after Mr Hancock said he would put his premiership on the line within days of entering Number 10 by putting his revised Brexit plan to the Commons.
He insisted the EU would shift its position and agree to a time limit on the backstop if the new prime minister could show they had support at Westminster.
He suggested EU leaders could sign up to the change at their summit in October ahead of Britain’s scheduled departure at the end of the month.
“The strength of my position will be the ability to show that the House of Commons, in principle, backs this new arrangement,” he told BBC Radio 4’s Today programme.
“They nearly proposed a time limit on the backstop before, but they didn’t think that the Prime Minister, Theresa May, would be able to get it through the House of Commons.”
Meanwhile the former leader of the House, Andrea Leadsom, launched her leadership bid with a promise that delivering Brexit by October 31 would be a “hard red line”.
“Over the past three years politics has failed dismally, it has failed to deliver on the biggest democratic decision in our history,” she said.
“Fulfilling that democratic decision is urgent and vital, it cannot and will not be put off any longer.
“Leaving the EU on October 31 is, for me, a hard red line.”
In contrast, former chief whip Mark Harper, who also launched his campaign on Tuesday, warned that the parliamentary arithmetic meant no new leader could guarantee Britain would be out by the Halloween deadline.
“One thing I’m not promising, as much as I’d like, is that we will leave deal or no deal come October 31,” he said.
“It just isn’t possible. As a chief whip who has had to operate when the numbers were tight, I know how Parliament works and I know how to count.”
Boris Johnson, who has so far avoided TV and radio studios, is facing growing criticism over his unwillingness to take to the airwaves to defend his promise to leave, deal or no deal, by October 31.
Mr Hancock told the Today programme: “I certainly think that everybody who puts their name forward to be prime minister should be open to scrutiny, should be accountable, should come on the Today programme and on other broadcast programmes.
“I think everybody should participate in the proposed TV debates and I think we have got to ask the question, why not?”