Tory trousers

Kevin Maguire in the Mirror gets the sentiment right but the language wrong when he writes of David Cameron:
He's all Tory mouth and no trousers.

Shame, as Cameron's a textbook definition of the actual meaningful phrase, 'all mouth and trousers'. He's often to be seen in those 'casual' focus-grouped dad jeans (anything but striped Eton trews), but the lack of substance is somewhat deeper.