If I was Ed Miliband, I would've whipped my MPs to vote for the motion.
240ish loyal Lab MPs + 85ish Tory rebels = real trouble for the PM
Actually I think that might have been counterproductive; it's easier to turn the screws on rebels when there's something big at stake. Cameron over-reacted over this as was; had Miliband declared a three-line whip in favour of the motion, Cameron might actually hinted that the vote was a confidence matter. So less Tory rebels. Not just that, but there are a lot of vocal pro-EU voices in the PLP. Anyways, the thing is (and what I'm trying to get at, maybe) is that rebellion is habit-forming. So if you want as many Tory MPs as possible to have a record of rebellion, then...