A senior aide to the House of Commons Speaker has reportedly tried to leak damaging information about Labour MPs to Michael Howard.

The Times says that this was the reason for the sudden departure this week of John Stonborough, who had worked for the past three years as a public relations consultant to Michael Martin.

Stonborough apparently resigned two days after being confronted about an e-mail, apparently sent under his name, that included material about MPs' expenses designed to embarrass the Labour Party.