Jeremy Hunt has raised the prospect that Ruth Davidson could be a member of his Brexit negotiating team as he questioned whether Boris Johnson was trustworthy enough to secure a new deal from Brussels.

As Mr Johnson broke cover to hit the campaign trail, stung by the Foreign Secretary’s charge of cowardice for staying away from the media spotlight, the underdog emphasised how character was the key test in the contest to succeed Theresa May.

“The judgement is: who is the person we trust as PM to go to Brussels and bring back that deal? It’s about the personality of our PM. If you choose someone where there’s no trust, there's going to be no negotiation, no deal. And quite possibly a general election which could mean we have no Brexit either.

“If you choose someone that the other side will talk to, who’s going to be very tough, there will at least be a negotiation and a deal to be done,” Mr Hunt told the BBC’s Laura Kuenssberg.

But the Surrey MP, when asked directly if his opponent could not be trusted, replied: “No. I'm saying I am trustworthy and I can be trusted to deliver this deal and I've got a background as an entrepreneur, as a negotiator, someone who's done very big complex negotiations like getting the extra £20 billion for the NHS, which I did when I was Health Secretary…So, I can deliver that.”

In a distinct change from the Prime Minister’s approach, Mr Hunt stressed how he would have a new-look Brexit negotiating team of not just UK Government ministers but also others to prove to Brussels Westminster could be brought on board.

“We have to approach this differently. It's the biggest constitutional crisis I can remember and the key is to put together a negotiating team for Brexit that will demonstrate to the EU we can deliver Parliament.

“So, what I do differently to what we've had before is I would have the DUP in my negotiating team, I'd have the ERG who are the Brexit purists, I'd have the Scottish and Welsh Conservatives, because, fundamentally, there is a deal to be done…This is doable.”

Asked if Ms Davidson, the Scottish Tory leader, could be included in Mr Hunt’s team, a senior source in his campaign later told The Herald: “To be determined but something that makes the EU confident we have the team that could get the deal through Parliament.”

The Foreign Secretary claimed the Irish backstop, the guarantee to keep the border with the Republic open, would have to be changed, using a “technology-led solution”.

He suggested “within the next decade” big border checks would be dispensed with as everything would be done online.

When pressed if such a solution – once dismissed by EU chiefs as “magical thinking” – could be implemented immediately, he replied: “Yes, I do…it’s about taking a smart approach”.

The Cabinet minister insisted departure on October 31 “come hell or high water is a fake deadline, because it’s more likely to trip us into a general election before we’ve delivered Brexit and that would hand the keys of No 10 to Jeremy Corbyn and then we'd have no Brexit at all”.

Mr Hunt also said he would want to cut taxes for ordinary people, slash businesses’ corporation tax, increase defence spending by £15 billion, ”fire up” the economy to boost growth and encourage people to save for their social care as they did for their pensions with the “reward” of a cut in costs.

Admitting he had wanted to be PM for 30 years, he added: “I would love to do this job. I can make a difference. This is a moment where if we send the right person, we can't just solve Brexit but we can open a whole new chapter in our history, an exciting chapter, and that’s what I want to do.”

Earlier, the Foreign Secretary riled the SNP by announcing the Foreign Office would no longer “offer support to Nicola Sturgeon if she goes abroad to drum up support for independence".

But the First Minister’s spokesman made clear she was “not going to be prevented from saying what she thinks in terms of Scotland's future”.