David Cameron on Sunday night looked as though he had weathered the recent storm over drug use that has engulfed his campaign for the Conservative leadership after his main rival said he had “absolutely got the right” not to answer questions about the issue.

As Conservative MPs prepare to decide this week which two men will battle over the leadership in a nationwide poll of party activists, David Davis, one of the leadership front-runners, said the row over Mr Cameron and drugs would quickly “fade out”.