MashGet

The Conservative leader was told that he had a "public duty" to ensure that Andy Coulson, the party's communications chief, answered questions about his editorship of the Sunday tabloid amid allegations that journalists working for him regularly used private information relating to high profile figures gained by hacking into phones to get stories.

During a surprise ambush outside a care home in Norwich, where Mr Cameron was campaigning ahead of a by-election later this month, Mr Clarke, whose constituency is in Norwich, handed the Tory leader a letter warning him that his own credibility was on the line over the scandal.