Too many Tweets make a twit: David Cameron accidentally congratulates a parody account of his colleague

Prime Minister David Cameron should probably have taken heed of his words in 2009, that "too many Tweets might make a t**t". He (or more likely his office) has tagged a parody account of Iain Duncan Smith:

Some recent Tweets from the mock profile:

It's been pointed out that it's not the first time the David Cameron Twitter account has made such a gaffe: