Heh, there is absolutely no way that the Conservatives will let the UK leave the EU. This is an empty promise to try and stop their grassroots voting UKIP.

The thing it, while many of the people who vote Tory want the UK to leave Europe, the people who actually fund the Conservative party make a lot of money from being part of the EU. The disconnect between the voters and the funders of the Conservative Party has been a defining feature of theirs for decades.

This is why mentioning Europe is so destructive for them, because they have to stay in Europe, but cannot publicly admit that.