I'm also a Brit, and to be honest, the term "liberal" in a political context has lost all meaning for me since everyone seems to have their own definition of what it actually entails.

I blame Jeremy Thorpe

This seems to be the case for a lot of words these days.

That exemplifies the cultural hegemony. In the UK, liberals historically stood for laissez-faire economics and minimal government intervention (among other things). Before the rise of the Labour Party, the main second party in the UK was the Liberal Party, which supported laissez-faire capitalism, in contrast to the Tories of the day, who tended to oppose free market capitalism and support paternalistic social and economic programs that benefited the nation as a whole, not just the rich (obviously that's changed—classic liberals now dominate the Tory Party). Lots of people still use liberal in this way (classically liberal), but the meaning has gradually changed under the influence of the US, so many people are unaware that liberal could mean anything but vaguely left-leaning and progressive.