The nature of the First Past the Post electoral system that we have in the UK is that there is room for two 'main' parties and one "none of the above" party that will hoover up most of the remaining votes. In the UK, and for a long time, that NotA party was the Liberal Democrats. However, as soon as they entered into coalition with the Tories (could have been Labour; the effect would have been the same), they became a "one of the above" party, and ceased to have any purpose - since if people wanted a Labour or Tory government, they would vote accordingly.
In the UK, in 2014, the "none of the above" party are now UKIP.
And that's it: Labour and the Tories are the two 'main' parties, the Lib Dems retain some little relevance because they're not quite dead yet, and the SNP and PC are relevant in Scotland and Wales respectively (and Northern Ireland, of course, has its own parties).
But how is it, I wonder, that we ended up with two largely-indistinguishable centre-right 'main' parties and, as our only viable alternative, a mid-right Thatcherite party that wants to cut us off from our biggest export market? If a people really do always get the politicians they deserve, what can we have done that is so terrible as to deserve that as our 'choice'?
#49: "Pathfinder: Lords of Rust", by Nicolas Logue
#50: "Bleak House", by Charles Dickens (a book from The List)