Tobias Ellwood, the Tory chairman of the Defence Select Committee, told the BBC that the war in Ukraine must not be used as a “fig leaf” when it comes to discussing whether to oust Boris Johnson.
Some MPs have argued against changing leader now because of Russia’s ongoing invasion.
But Mr Ellwood said: “Let’s just park this Ukraine fig leaf because the capability that is offered to any prime minister, the MOD machine of options, of risk assessments, of recommendations, will remain the same.
“We actually changed the head of the Armed Forces… last December when there was a build up, we knew an invasion would take place.
“We can do that simply because we have a very profession, Rolls Royce machine of advice supporting the National Security Council and indeed any prime minister of the day.”
He repeated his call for Mr Johnson to “offer his own timetable” to submit to a confidence vote.