The race to become the next Conservative Party leader has begun, following Theresa May's announcement that she will step down next month.
Health Secretary Matt Hancock is the fifth Tory to enter the race.
He told the BBC that delivering Brexit was "mission critical" and Mrs May's successor must be more "brutally honest" about the "trade-offs" required to get a deal through Parliament.
The leadership contest will determine who is the UK's next prime minister.
Party bosses expect a new leader to be chosen by the end of July.
Mrs May confirmed on Friday that she will resign as party leader on 7 June, but will continue as PM while the leadership contest takes place.
She agreed with chairman of the Tory backbench 1922 Committee, Sir Graham Brady, that the process to choose a new leader should begin the week after she stands down.
Five candidates have confirmed their intention to stand:
- Foreign Secretary Jeremy Hunt
- International Development Secretary Rory Stewart
- Health Secretary Matt Hancock
- Former Foreign Secretary Boris Johnson
- Former Work and Pensions Secretary Esther McVey
Announcing his candidacy, Mr Hancock ruled out a snap general election in order to resolve the Brexit stalemate, saying this would be "disastrous for the country" and would risk seeing the Labour leader Jeremy Corbyn in power "by Christmas".
Instead, he said his focus would be on getting a Brexit deal through the current Parliament and "levelling" with MPs about what this would mean for the UK.
He told Radio 4's Today programme he would be more upfront than Mrs May had been about what compromises the UK would have to make to continue to access EU markets.
He said there was no point in becoming prime minister unless he was straight-forward about the trade offs – "between sovereignty and market access and the trade-offs to get a deal through this Parliament".
He also said the party needed a "leader for the future not just for now", capable of appealing to younger voters.
"We need to move on from the horrible politics of the last three years," he said.
"We need a fresh start and a fresh face to ensure this country wins the battles of the 2020s and remains prosperous for many years to come."
'Huge tensions'
Mr Stewart warned other candidates to tell the truth about what a no-deal Brexit would mean.
"There are huge tensions in the race," he told Radio 4's Today.
"People will be encouraged to promise things they can't deliver… the most dramatic of which are people who are going to be encouraged to promise a no-deal Brexit."
He said Parliament would simply not vote for leaving the EU without a deal and, even if the UK did leave that way, it would leave the country in a limbo.
"It is not a destination. It is a failure to reach a destination. What they are probably promising is failure, delay and endless uncertainty."/BBC