The Grantham MP Nick Boles has resigned from the Conservative party.
He made the announcement in the House of Commons late last night after his Brexit proposal was defeated.
The MP blamed his decision on his fellow Tories for being unable to compromise.
He was already facing de-selection by the Grantham constituency who were unhappy about his approach to Brexit.
Nick Boles' proposal to stay in a Common Market was defeated by 282 votes to 261. His plan sought UK membership of the European Free Trade Association and European Economic Area.
It was among four Brexit alternatives to Theresa May's deal rejected again by MPs.
In his commons announcement he told MPs he "could no longer sit for this party."
This prompted one colleague to shout: "Oh Nick, don't go, come on," while other MPs gave him a round of applause.
He later wrote on Twitter: "I am resigning the Conservative whip with immediate effect.
"The Conservative Party has shown itself to be incapable of compromise so I will sit as an Independent Progressive Conservative."