News International conducted a sustained campaign to access personal information of former Prime Minister Gordon Brown, it has been claimed.

The Sunday Times is said to have obtained information from Mr Brown's lawyers and The Sun appears to have accessed medical records about his son's health.

Police have told the Browns that there were references made to them in the notebook of Glenn Mulcaire, the private investigator who hacked phones for the News of the World.

Meanwhile, Abbey National found evidence Mr Brown was the victim of blagging after someone contacted them pretending to be the former Prime Minister.

The campaign against Mr Brown appears to have been prolonged and sustained, covering his legal, financial and personal details.

It all comes on the day that News International's bid for BSKYB was referred to the Monopolies Commission by the Government and two MPs called for the resignation of the senior Scotland Yard detective who ruled out a further inquiry into the phone hacking scandal.

Labour's Chris Bryant urged Assistant Commissioner John Yates, who reviewed the initial investigation into phone hacking in 2009 but ruled there was no further evidence, to resign.

Mr Yates, currently the Met's most senior counter-terrorism officer, was guilty of "repeatedly lying" to MPs, Mr Bryant said, while his Labour colleague Tom Watson (West Bromwich East) said the detective's position was now "untenable".