The director of public prosecutions will issue new guidelines later this month, clearly setting out the factors that must be considered when deciding whether to prosecute journalists.

Keir Starmer QC told the Leveson inquiry that the Crown Prosecution Service has no specific policy relating to journalists who may try to rely on a public interest defence, and that it would be "prudent" to set out the factors in one place for easy reference.

An interim policy will be published within weeks, and a public consultation will run for 12 weeks to allow for input into the formal policy.

Starmer told the inquiry: "It would be prudent to have a policy that sets out in one place the factors that prosecutors will take into account when considering whether or not to prosecute journalists acting in the course of their work.

"That will make things clearer. I hope to have that ready within a matter of weeks."