This has been a stinging rebuke to David Cameron's authority. He has taken a battering on this all week but really the House of Commons has sent him a very clear message - there have been a large number of rebels on his own side who have said that they don't want to go down his route.
The motion that has just been voted down assumed that President Assad's regime was responsible for a chemical attack. That is something that many people in the House of Commons took exception to. They insist that weapons inspectors have to provide their evidence first.
This begs all sorts of questions: What will America do now? Can they go ahead on their own? The French are holding a vote next week - what will they do?