New information on the alleged scale of phone hacking by News International journalists has come to light at the first Leveson Inquiry hearing today.

Robert Jay QC, the Inquiry Counsel, told Lord Justice Leveson in court 73 at the Royal Courts of Justice, that "the Sun" and "the Mirror" were 'corner names' (those commissioning hacking transactions, written in the corner of the notebook) in private investigator Glenn Mulcaire's notebooks.

He also revealed that at the time of the trial of Mr Mulcaire and NoW royal correspondent Clive Goodman in 2005/06, five other NI employees, referred to as A, B, C, D and I, commissioned information from Mr Mulcaire.

Mr Jay told the Inquiry there was evidence in Mulcaire's notebooks of 2266 'taskings', and about 28 legible ‘corner names’. He said four journalists accounted for 2,143 of those 'taskings'.According to the QC, when police raided Mr Mulcaire's offices in 2006, they also found 690 audio recordings along with notebooks. Thirty eight of those recordings are of Mr Mulcaire's 'blaggings'.In addition, Mr Jay said 586 voicemail messages, intended for 64 people were intercepted by Mr Mulcaire between 2004 and 2006, as well as 318 calls made to voicemail numbers.

Lord Justice Leveson, opening the proceedings, said the inquiry would be asking one simple question: "Who guards the guardians?"

Freedom of the press and freedom of expression must be exercised "with the rights of others in mind", he said.

The judge had previously asked newspaper editors to make suggestions of new approaches to press regulation.

He said: "Those ideas must reflect the fundamental freedoms to which I have referred."

He added: "But it must also recognise that 'guard the guardians' is not an optional add-on."

Neither is it good enough if it does not take account of the legitimate public concern, not only about phone hacking, but also other unethical behaviour not justified by what is truly in the public interest."