Sir John Redwood said it was time for Parliament to "fulfil the wishes" of the British public on Brexit.
The Conservative MP said politicians had opted to "fight" against the outcome of the 2016 referendum, and called for consensus among his colleagues on the next steps in Britain's exit from the EU.
"Parliament decided to fight the people for three years and what a mess it has made of it," he told talkRADIO's Julia Hartley-Brewer.
A Labour motion to block a no-deal Brexit was rejected in a Commons vote earlier this week, ahead of the first round of voting on the Tory leadership contenders.
And there was also concern among some MPs that the leadership candidates in favour of a no-deal Brexit would suspend Parliament in order to push it through without objection.
"If this Parliament at the last minute finds some new device we haven't yet thought of to stop it all, heaven help the Parliament," Sir John added.
"If they cannot agree on an agreement then they have to accept leaving without the agreement, and that is crystal clear."
He continued: "That is what the public, by a very large margin, is telling them through recent elections and opinion polls."
The MP for Wokingham voted for Boris Johnson to become the next Tory leader in yesterday's ballot.
And he defended Mr Johnson's lack of appearance in the media, which has been widely criticised as the leadership race continues.
"I want Boris to maximise his time with those MPs that don't yet support him," Sir John explained.