For the ruiling party to reach third place in a two-and-a-half party system is a damning sign of British disfavor of Prime Minister Gordon Brown. Some dislike Brown because he is too similar to former Prime Minister Blair's centrist "New Labour" mold, others oppose him because he is different and snubs Americans and the War on Terror. Needless to say not too many people like him.
American readers should understand one thing about the Conservative Party. This is not the strong neo-liberal Thatcher Conservative Party nor is it the "party in power" Major Conservative Party. David Cameron's Conservative Party describes itself as compassionate conservative. This means more welfare state just with reforms, a European outlook as equal to cross-Atlantic outlook, and big on the environment. Think Arnold Schwarzenegger.
While this election does not change the overall British leadership, look for Labour to fight for its life against a swell of calls for an election that would favor the Conservative Party.