Culture Secretary Ms Dorries repeatedly sought to blame Remainers for plotting against the PM in interviews this morning following another bruising week for Mr Johnson.
However, out of the 15 Tory MPs who have so far publicly called on Mr Johnson to go, just seven of those had publicly backed remaining in the EU in the 2016 referendum.
But Ms Dorries told Times Radio: "There are a small number of voices, whether they are people who were ardent supporters of Remain, who see this as their last opportunity to reverse Brexit."
Ms Dorries was also forced to insist Mr Johnson tells the truth as the PM came under sustained pressure over the future of his premiership.
She said Mr Johnson told the truth "to the best of his knowledge" based on what he was told by his aides.
Challenged about a claim made by Mr Johnson in the Commons about the number of people in work before and after the pandemic, Ms Dorries told BBC Breakfast: "He will have been given by advisers and researchers the fact that there were more people in work than there were at the beginning of the pandemic not on the payroll."
She said: "So did he tell the truth when he quoted that? Yes, he told the truth as it was given to him.
"I can personally tell you that the Prime Minister, when he stands at the despatch box and makes quotes like the one you just quoted, is because the researchers and his advisers will have given him that quote, and that's... and he was truthful, to the best of his knowledge, when he made that quote," she said.
Ms Dorries added: "The Prime Minister does tell the truth."
Honesty was one of the key reasons former minister Nick Gibb said on Friday that he could no longer support the PM, and had submitted a letter of no confidence to Sir Graham Brady.
Writing in a national newspaper, Mr Gibb, MP for Bognor Regis and Littlehampton, said his constituents were "furious about the double standards" and he said the Prime Minister had been "inaccurate" in statements to the Commons.
The MP said: "To restore trust, we need to change the Prime Minister."
The number of Tory MPs who have now publicly called for Mr Johnson to resign stands at 15.
Mr Johnson also lost five No 10 aides in 24 hours on Thursday and Friday. But Ms Dorries insisted 97 per cent of Conservative MPs were behind the Prime Minister.
Other Tory MPs are expected to consider over the weekend whether to write to the chairman of the 1922 Committee Sir Graham Brady in an attempt to force a leadership contest.
Mr Johnson was facing fresh accusations surrounding so-called ‘partygate’ after newspaper reports that Metropolitan Police have a photograph of Mr Johnson holding a beer at an alleged gathering in June 2020 to mark the Prime Minister's birthday.