Boris Johnson has claimed only he can see off both Nigel Farage and Jeremy Corbyn as he urged Tory MPs and party members to make him their next leader and prime minister.
The leadership campaign frontrunner, who is up against the likes of Michael Gove, Jeremy Hunt and Dominic Raab, has claimed he would refuse to pay the promised £39bn divorce bill to the European Union unless better Brexit terms are on offer.
He added that he would step up preparations to counter no-deal "disruption", and told the Sunday Times that he could defeat the twin threat posed by the Brexit Party and Labour leaders.
Comparing them to the sea monsters from Greek mythology which troubled Odysseus, he said: "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 31 October and delivering a One Nation Tory agenda."
He 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.
Mr Johnson said the £39bn settlement would only be paid when there is "greater clarity" about the way forward.
"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."
The former foreign secretary has so far received backing from prominent Brexiteer Steve Baker, and has also picked up endorsements from cabinet ministers James Brokenshire, Chris Grayling and Alun Cairns, and former international development secretary Priti Patel.
Meanwhile leadership rival Sajid Javid's campaign has received a boost with an endorsement from Scottish Tory leader Ruth Davidson.
Her decision to back Mr Javid came as he set out his own plan to tackle the Irish border issue by spending hundreds of millions on a technological solution.
The Home Secretary said there is a moral duty on the UK to pay for measures at the Irish border in an effort to secure a Brexit breakthrough.
Rory Stewart's camp said he is the challenger best placed to take on Mr Johnson, pointing to polling by Opinium which puts the two leadership candidates neck-and-neck on the question of "would they make a good prime minister".
Dominic Raab ruffled feathers when he suggested the possibility of suspending parliament in order to secure Brexit if he was made Conservative leader and prime minister.
This would mean shutting down debate and sending MPs on holiday so they would be unable to have a say, potentially dragging the Queen into a constitutional row, a plan described as "unlawful" by Mr Stewart in a tweet.
Mr Raab said it was "very unlikely" it would be necessary to prorogue parliament in order to prevent MPs blocking a no-deal Brexit, but taking the option off the table would be a mistake.
"I think it's wrong to rule out any tool to make sure that we leave by the end of October," he told BBC Radio 4's Today.
"The exam question in this contest is 'who can be trusted to lead us out by the end of October and end this paralysing uncertainty'."
Following Theresa May's resignation as Tory leader on Friday, the race to replace her is in motion and the nomination process will take place on Monday.
Candidates require eight MPs to back them in order to enter the race, with the first round of voting on Thursday.
:: Home Secretary Sajid Javid and Foreign Secretary Jeremy Hunt will be appearing on Sophy Ridge on Sunday on Sky News from 9am this morning