Liz Truss has said it is time to "push the button" on Brexit, as she endorsed Boris Johnson as the "global player" the UK needs to lead it into "uncharted territory".
The Environment Secretary told ITV News Mr Johnson is the "type of person we need" as Prime Minister, as she lauded the "fantastic job" he did as Mayor of London.
The MP for South West Norfolk also called for swift negotiations on Britain's new relationship with the EU.
"In my view the British people have spoken, there's no going back," she said. "We do need to press the button on exit and get on with it, because there would be a huge gap in trust if we were not to deliver on what was a referendum with an incredibly high turnout.
"I personally didn't argue for that but... I believe when the people speak we need to listen and we need to deliver."
Michael Gove has become the first of the Conservative leadership candidates to publish his tax returns during the campaign.
Theresa May has secured the backing of Philip Hammond in her bid to succeed David Cameron ahead of the first round of voting on Tuesday.
A poll in the Sun on Sunday suggests the home secretary is able to count on the backing of six out of 10 Conservative MPs.