Sir Roger Gale says the Conservative Party should not hold a leadership election amid the war in Ukraine.
A senior Conservative MP has said it is "not the right or responsible moment" for UK Prime Minister Boris Johnson to resign over the 'partygate' scandal.
Sir Roger Gale told Euronews that Johnson should remain in his position amid the "international crisis" sparked by Russia's invasion of Ukraine
The UK PM and Chancellor Rishi Sunak both apologised after they were fined for illegally attending parties at the height of the COVID-19 pandemic.
Both have faced fierce calls to quit from opposition MPs, but have received the support of cabinet members and many Conservative politicians.
Gale admitted: "Under normal circumstances, I would expect the Prime Minister to resign.
"The Prime Minister has broken the law, the Prime Minister has misled the House of Commons, and the public anger cannot be underestimated.
"But we are facing the gravest crisis that Europe and the world has faced since 1945, I don't believe that responsibly we can call for a leadership election in the middle of this international crisis."
On Wednesday, UK justice minister David Wolfson resigned, stating that the prime minister’s actions were “inconsistent with the rule of law”.
In a letter posted on Twitter, Lord Wolfson said he had “no option other than to tender my resignation”.
Gale - the MP for North Thanet in Kent - became the first Tory to publically submit a letter of no confidence in Boris Johnson over the 'partygate' scandal.
But the 78-year-old told Euronews that the potential "nuclear" nature of the war in Ukraine means the UK needed a stable government.
"I believe the time is going to come when this Prime Minister will have to be replaced," he said.
"We cannot have a lame-duck Prime Minister leading the government at this particular moment in time.
"While I stand by everything I have said in the past about [Boris] Johnson ... I don't believe that now is the right moment or the responsible moment to seek to do that," he added.
Click on the player above to watch the full interview.