I don't think you realize the logical disconnect of your statement. No one voted for Labour or the LibDems because David Cameron wasn't conservative enough. Their is no conservative answer for the UK, because the UK is no longer a conservative country. It's a solidly socialist country.
If Cameron had run on a platform of privatizing health care, cutting social services and lowering taxes on the people who help provide capital formation, he would have been lucky to get 25% of the vote, not the 38% of the he managed.
Cameron gained 97 seats, but still was 20 seats short. The socialist got 258 seats, and the profoundly socialists got 25 seats. The balance of Parliament went to parties that are WELL to the left of the LibDems.
It's not Margaret Thatchers UK anymore.
Unfortunately it’s not Reagan’s US anymore, either