Depending on what happens with the Government's same-sex marriage legalization plans, traditional Tory voters may very well be inclined to join the ranks of the rabidly anti-gay UKIP, especially if the bill is approved by the House of Commons, which appears to be a near certainty, despite an internal Tory rebellion on the issue.
This will help Labour and Ed Miliband ride to an easy victory with a comfortable majority in the new House of Commons. UKIP will undoubtedly enter Parliament and will, in all likelihood, either surpass or come very close to surpassing the vote received by the LibDems.
No. The same sex marriage legislation is a free vote. The thing is, the same sort of constituent wrote to the same sort of MP who hummed and hawed over the civil partnership legislation in 2005. It's the same argument now re-hashed. Difference was the Tory party was whipped to vote in
favour of the legislation by Michael Howard. There was no division then in the party and no impact at the General Election the following year.
As for the Lib Dems, they exist as a collection of MP's rather than as a 'party' at the GE and a significant number of them will hang on in 2015 even if the national result for them is poor.
The vote will pass with a majority of something like 150-200 in the Commons with Tory backbenchers, rural troglodytes and the Gavin Shukers of the Labour Party voting against. And no one will care or remember come the GE.