MPs' backing of Referendum Bill 'doesn't guarantee vote'

This in itself doesn't guarantee it [a vote in the next Parliament], although of course if we got his onto the statute book and made it law then it's much harder for other parties to turn against it in the future.

And the Bill we have passed two years ago - the Act of 2011 now requires a referendum if any British government gives away more powers to the European Union now has been accepted by all the other parties.

– William Hague, Foreign Secretary