"On every morning that you wake up for the rest of your life you will be ashamed of what you did last night" -- David Margesson to John Profumo, May 9, 1940.
John Profumo was a young Tory member of Parliament who had been elected in April 1940 on a pro-Nevile Chamberlain platform. As the early course of World War II turned against the Allies, on May 8, 1940, the House of Commons held a confidence vote on Chamberlain's government. Profumo was serving in the Army when elected, and received a day's leave to attend the vote. As the members filed off into the lobbies to vote, Profumo, almost on a whim, joined 41 other government supporters in calling for Chamberlain's resignation.
Chamberlain's government won the vote, but it was obvious that he was mortally wounded as Prime Minister. Profumo, his duty done, then went off to a night club and proceeded to get drunk.
The next morning, Profumo was called to the office of the Tories' Chief Whip, David Margesson, who made that fateful prediction. Profumo returned to his unit.
The following day, May 10, 1940, the German war machine struck west, invading Belgium. By that evening, Winston Churchill was Prime Minister.
John Profumo would later take down another Conservative government, after sharing a bed with a woman sharing a bed with a Russian diplomat and lying about it to the House of Commons. But his action helping to take down the Chamberlain government in the end helped to save Western civilization.