We now have senior Conservative politicians saying that others should leave but there is no mention of them going to the backbenches themselves.
It is my belief that there is a fundamental flaw in the system.

We have a form of dictatorship, this is also true of many so called democracies. The Prime Minister can choose his/her ministers or sack them as she wishes, these means if any person disagrees with her she can ask them to resign or sack them. This way she finishes up with a load of sycophants,
To my mind the choice of who should be  a Minister or Secretary of State should be the choice of all members of the political party in power. The same should apply when asking them to resign.