Ruth Davidson has called for a "period of silence" among her Conservative colleagues to allow the prime minister to get a Brexit deal "over the line".
The Scottish Tory leader said the two years following the EU referendum had provided enough time for debate.
Her comments follow Boris Johnson's description of the Chequers plan as "deranged and entirely preposterous".
She told the BBC's Sunday Politics Scotland it was now time to get behind the prime minister.
As Tory activists assembled in Birmingham for their party conference, she said: "There's been time over the last two years for debate.
"The former foreign secretary was in one of the great offices of state during the time that much of this plan was being constructed - and praised it as soon ago as November of last year.
"Now is the time for Conservatives to get behind the prime minister, give her the space to get the deal done and to back her to deliver for the country.
"In terms of a period of silence, I would be very welcoming of one."
Her comments followed another strident intervention in the Brexit debate by the former foreign secretary, Boris Johnson.
He told the Sunday Times: "Unlike the prime minister, I fought for this, I believe in it, I think it's the right thing for our country and I think that what is happening now is, alas, not what people were promised in 2016."
Theresa May later insisted she did believe in Brexit, telling the BBC's Andrew Marr programme that the Chequers plan had the ability to deliver a good free trade deal with the European Union.
Ms Davidson also said she would go into the next election with a manifesto commitment to block a second Scottish independence referendum because in 2014 "the people of Scotland were promised this would be a once in a generation event".
Asked about calls for another referendum on any Brexit deal, she said: "In terms of our history in Scotland, I've been pretty vocal about the fact that you can't re-run referendums if you are a nationalist because you didn't get the result you want.
"I'd be pretty hypocritical if I said you could re-run this Brexit referendum because it wasn't the result the I argued for."