Peter Bone has called for Theresa May to step down "straight away".
The Conservative MP told talkRADIO's Julia Hartley-Brewer that the country could not "move forward" until she left her role as Prime Minister.
"The Prime Minister has accepted she has to go, the question is when," he said.
"For me it should be straight away and we can get on with choosing a new Prime Minister, otherwise we're going to limp along week by week not dealing with any legislation, not dealing with Brexit and that is just not tolerable."
Mr Bone's appearance on the breakfast show followed calls for Mrs May to set her departure date, after the 1922 Committee ruled out a leadership contest before December.
"I have always argued I want to change the policy, not the Prime Minister. As the Prime Minister won't change the policy, we clearly have to change the Prime Minister - and quickly for the interests of the country," he added.