The first party is Tony Blair's, Labour, sort of centre-left. The second is the Conservative Party, sort of centre-right, with a new young leader called David Cameron. And the third (and smallest) party is the Liberal Democrats, sort of centre-centre, with, as of this weekend, no leader at all.
The reason for this is that their old leader, a man called Charles Kennedy, has fallen on his political sword – just before he fell flat on his face the worse for drink. He resigned, under pressure, after bravely admitting to one of politics's worse kept secrets – he has an alcohol problem.
You would have thought that his colleagues would have supported him through this difficult time but they couldn't wait to circle him and stick the boot in.
Charles Kennedy was one of the nicest men in politics and one of the most effective. He led the Liberal Democrats to their greatest electoral success in 80 years But if he was hoping for old fashioned liberal compassion, decency and tolerance from his party he was either barking up the wrong tree or barking mad.
There have been many powerful men who have suffered with an alcohol problem. Winston Churchill and your own George W to name but two.
Charles Kennedy deserved better treatment, not just as a successful political leader but as a human being. We all knew that Charles liked a drink and we all guessed that it was probably more serious than a few glasses of wine after a hard day. To some degree we were all complicit in his continuing to drink secretly.
Those journalists closest to the political centre of this country kept quiet about his drinking because he is such a likable chap and, let's be honest here, a lot of journalists like a tipple or two and misery does enjoy company.
The loss of Charles Kennedy to our political circus will be felt for a long time. The cruel way that his own party treated him will effect them for much, much longer. They had, until now, lived with the glorious reputation of being Britain's 'nice party' but this surely must have ended.
The truth is that Charles Kennedy's drink cabinet has been a better friend to him in recent months than his own back-stabbing cabinet in waiting.