Frontrunners in the Tory leadership race insisted they could somehow succeed where Theresa May failed in striking a better Brexit deal with Brussels.

The European Union has repeatedly said it would not reopen the Withdrawal Agreement, but Michael Gove – seeking to get his campaign back on course after revelations over his past cocaine use – said “changing the prime minister changes everything”.

Jeremy Hunt claimed German Chancellor Angela Merkel told him the European Union (EU) “would be willing to negotiate” on the Brexit deal with a new prime minister.

Boris Johnson would use the £39 billion divorce bill to secure a better deal, refusing to hand over the cash unless improved terms were on offer.

And Sajid Javid said he would offer to spend “hundreds of millions” on a technological solution to the Irish border question.

Brussels’ chief negotiator Michel Barnier has stressed that the deal struck with Mrs May remained the only one on the table and “a new prime minister will not change the problem”.

But Mr Gove told the BBC’s Andrew Marr Show he would have a “smart negotiating team led by myself and other politicians, rather than officials, explaining to the European Union what needs to change in order to make sure we honour the referendum result”.

“We would have a full stop to the backstop, we would also have a clear approach to making sure that we have a Canada-style free trade agreement.”

He added: “Changing the prime minister changes everything. We can get a better deal.”

Mr Gove confirmed that he would be prepared to delay Brexit beyond the October 31 deadline for “days or weeks” if a deal was within reach.

Foreign Secretary Mr Hunt claimed the German Chancellor told him Brussels “would look at any solutions” the UK puts forward to solve the Northern Irish border issue.

Asked on Sky News’ Sophy Ridge On Sunday whether he was confident of renegotiating the Withdrawal Agreement, he said: “If you’re asking me as someone who has done deals all their life ‘is there a deal here?’, yes, there is.

“Finding that deal is going to mean approaching the EU with the right kind of person. If we go in with an ultra hardline approach, we will get an ultra hardline response.”

Mr Javid said offering to pay for changes at the border would secure co-operation from Dublin and Brussels.

“You don’t need a magic solution for this, the solution exists. We’ve done the homework on this,” the Home Secretary, who has ministerial responsibility for the UK’s borders, told Sky News.

Mr Johnson said he would scrap the backstop – something the EU has so far refused to do – and would settle the Irish border issue only when Brussels is ready to agree to a future relationship.

The £39 billion settlement would only be paid when there is “greater clarity” about the way forward, he told the Sunday Times.

“I always thought it was extraordinary that we should agree to write the entire cheque before having a final deal,” he said. “In getting a good deal, money is a great solvent and a great lubricant.”

In his first major interview of the campaign, the bookmakers’ favourite said only he could defeat the twin threat posed by the leaders of the Brexit Party and Labour – comparing them to the sea monsters from Greek mythology which troubled Odysseus.

“I truly believe only I can steer the country between the Scylla and Charybdis of Corbyn and Farage and on to calmer water.

“This can only be achieved by delivering Brexit as promised on October 31 and delivering a One Nation Tory agenda.”

Rory Stewart said Mr Johnson’s comments on the money and the Irish border were “undignified” and “irresponsible”.

The former foreign secretary has picked up support from James Cleverly, who pulled out of the leadership race and from prominent Brexiteer Steve Baker who had been considering his own run for the post.

He also picked up endorsements from Cabinet ministers James Brokenshire, Chris Grayling and Alun Cairns, and former international development secretary Priti Patel.

Mr Javid received a boost with an endorsement from Ruth Davidson, the popular leader of the Scottish Conservatives.