Actually the whole business in the Commons was pretty daft, because the amendment by Labour which failed to get passed effectively said the same as the Government motion that also failed to get through, just using different phraseology. Like the Government motion it said that things had to hold fire until the inspectors had reported to the UN.

Here is the Labour amendment

And this links contains the Government motion

So if the Government had accepted the Labor amendment and told its people to vote for it, it would have passed. But that would have involved losing face - which of course happened in any case when they lost the motion they had assumed would be passed. They play such silly games.