Glenn Mulcaire granted evidence appeal
The Supreme Court has ruled it will decide whether private investigator Glenn Mulcaire must reveal which journalists asked him to hack phones.
The court granted Mulcaire permission to appeal against two court orders that could have forced him to name the reporters.
The two-day hearing will begin on 9 May.
Earlier this month Mulcaire lost his appeal against the orders at the Royal Courts of Justice, but appealed.
He had appealed to try to avoid having to answer questions in civil proceedings that could incriminate him.
Mulcaire was jailed in January 2007 for six months along with the News of the World's royal correspondent Clive Goodman for illegally accessing voicemails of members of the royal household.
At the time he surrendered notebooks to the police containing information about phone hacking.
Mulcaire was contracted to the former newspaper to undertake "research assignments" from at least September 2001.
Comedian Steve Coogan and PR consultant Nicola Phillips, a former employee of the publicist Max Clifford, have since launched civil privacy cases against News International, the publisher of the now-defunct Sunday tabloid, and Mulcaire.
Currently, if questioned in the cases, Mulcaire would have to explain how he obtained voicemail numbers and passwords and who provided the details.
The Supreme Court only deals with the most important cases where the top judges have to decide on a point of law which is of general public importance.