We have a two party system. Or, if you take another view, currently just a one party one.
After the Lib Dem’s ill-fated brush with coalition government there isn’t a clear third party, after the Conservatives and Labour. The SNP, as the chart above illustrates, are in third position numerically. They are not party that can extend any further though – barring the 3 seats they didn’t gain at the last election. Also, given that their aim is the secession of Scotland from the union there is a self-imposed limit on the degree to which they would get involved in politics south of the border.
Beyond that there are very few concrete conclusions to be drawn. The Lib Dems put in solid seconds for 3rd place in most of the categories – except a little surprisingly leader recognition. UKIP bounce up and down depending on the different measures. The Greens (my party) have a huge gap between vote potential and voting intention.