Okay to ask Cameron about drugs... but not Brown?

The Labour Party is up in arms after the BBC's Andrew Marr had the temerity to ask Gordon Brown if he was on the happy pills.

Former leader Neil Kinnock told Five News: "The BBC is one of the greatest institutions in the world. They demeaned themselves, they cheapened themselves and the judgement of the journalist who asked the question has to be questioned."

So it is okay to ask David Cameron if he has taken drugs (twenty years ago) but not okay to ask the leader of the country if he does?

As usual, one rule for one...