The Speaker of the House of Commons - John Bercow - stunned MPs this week when he announced he was "strongly opposed" to US President Donald Trump addressing Parliament when he visits Britain.
It's already led one Conservative backbencher to table a motion of no confidence in him.
John Bercow is no stranger to controversy. His brutal put downs of MPs and ministers in the Commons have often grabbed the headlines.
Bullied at school because he was short, he began his political career on the far right - a member of the notorious Monday Club.
But over the years, in his own words, his political views have "mellowed" - to the point where many Tories now regard him as a traitor and plot to unseat him.
On Profile this week, Mark Coles examines the highs and lows of Speaker Bercow's life and career.
Producer Smita Patel Researcher Beth Sagar-Fenton.