Source: Commons divisions
UK Parliament · Commons Division 235 · 13 April 2016
266 Aye / 300 No · lost by 34 · 4 tellers (not counted) · 2 both
On an Opposition Day the largest opposition party chooses the topic of debate. The vote is symbolic, it doesn't change the law, but it forces the government to publicly take a position on the opposition's choice of question.
Totals are Parliament’s official count, which does not include the tellers. Parliament’s published list names 264 of the 266 Aye voters and 298 of the 300 No voters; tellers are listed and marked but not counted.
Walking through both the Aye and No lobbies is a recorded form of deliberate abstention.