How can a Conservative prime minister be ousted?

Boris Johnson has made a career of sailing close to the wind and has refused to resign despite several waves of MPs calling for him to do so.

British Prime Minister Boris Johnson (PA)

More Conservative MPs have put forward a letter of no confidence in Boris Johnson, as calls for him to resign as British prime minister continue.

Tories Andrew Bridgen and Elliot Colburn confirmed on Monday that they have handed in no-confidence letters, joining a growing number of colleagues.