Tory leadership hopeful Sajid Javid has welcomed an endorsement from Scottish leader Ruth Davidson as he bids to replace Theresa May.

Davidson's 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 support of Davidson, a popular figure in the party, was welcomed by Javid who said"Ruth knows a winner when she sees one,".

Speaking to the Mail on Sunday, the Home Secretary also 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.

He said: "I think it's morally justified to pay for that because we both have signed the Good Friday Agreement, we are both absolutely committed to peace on the island of Ireland and - given that we voted to leave and that's what's changing the status quo on the island of Ireland - I think it's morally right that we say, 'look, we'll pay because we've caused this'."

Meanwhile Michael Gove sought to focus once more on policy issues after the revelations about his past cocaine use.

Writing in the Sunday Telegraph, he set out a "pro-business economic plan" to take on Mr Corbyn's "Marxist message".

Gove said his plan would mean "reducing the regulations which hold business back", cutting taxes and "using the opportunity of life outside the EU to look to replace VAT with a lower, simpler sales tax".

However, front-runner for the role 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 the next prime minister.

Johnson said he would refuse to pay the promised £39bn to the European Union unless better Brexit terms are on offer - and would step up preparations to counter no-deal "disruption".

In his first major interview of the campaign,he told the Sunday Times 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."

But Rory Stewart's camp said he is the challenger best placed to take on Mr Johnson, pointing to polling by Opinium which puts him neck-and-neck with the former foreign secretary on the question of "would they make a good prime minister".

Mr Stewart said it is "very encouraging", but he cautioned there are "many steps still between here and Downing Street".

As Theresa May resigned as Tory leader on Friday, the starting gun was fired for the race to replace her.

The nomination process will take place on Monday, with candidates requiring eight MPs to back them in order to enter the race, with the first round of voting on Thursday.