THE future of Sir Paul Stephenson, commissioner of the Metropolitan Police, is uncertain after it emerged that he enjoyed a free five-week stay at a luxurious health farm promoted by the former deputy editor of the News of the World.

Sir Paul stayed at Champneys in Tring, Hertfordshire, while recovering from a broken leg in January this year. The spa was being promoted by Outside Organisation, a public-relations firm whose managing director was Neil Wallis -- the former deputy editor of the News of the World who was arrested last week in connection with the phone-hacking scandal.

A Metropolitan Police spokesman confirmed that Stephenson had stayed for free at Champneys while recovering from the fracture, but denied any suggestion of impropriety and said that Stephenson had declared the stay.

In 2009, the Met hired Wallis as a £1000-a-day consultant. It is understood that he advised senior officers involved in the hacking affair.

Stephenson also had lunch or dinner with News International executives 18 times throughout the period covering the scandal, including eight occasions with Wallis while he was at the News of the World.

And he was offered hospitality by News International on 15 occasions between April 2007 and March 2010, accepting 14 of the invitations.

Assistant Metropolitan Police commissioner John Yates also had regular dinners with News International company executives and editors.

Meanwhile, Foreign Secretary William Hague was forced to defend the Prime Minister yesterday as criticism mounted of David Cameron’s persistent links with Rupert Murdoch’s media empire. Downing Street revealed on Friday that Cameron paid for the tabloid’s former editor, Andy Coulson, to stay overnight at the Prime Minister’s country residence, Chequers, in March. By this point the Metropolitan Police investigation into phone hacking was under way.

Coulson was arrested by police and bailed nine days ago.

Cameron has also had 26 meetings with executives of Murdoch’s News International (NI) and News Corporation since entering Number 10, including two stays at Chequers last year by ex-NI chief executive Rebekah Brooks. She resigned on Friday.

Cameron has been accused of appalling judgment in hiring Coulson to lead the Tory party’s press operation in 2007, just months after he stood down as editor of the News of the World following the jailing of its royal editor in connection with the hacking of mobile phones.

However, Hague said in an interview with the BBC: “In inviting Andy Coulson back [to Chequers] the Prime Minister has invited someone back to thank him for his work … that is a normal, human thing to do. I think it shows a positive side to his character.”

The comments came as Rupert Murdoch and his son James appeared increasingly isolated at the top of the family’s media empire after a cull of senior executives failed to silence critics.

Rupert Murdoch yesterday took out large-scale newspaper adverts to issue a signed apology for the hacking scandal -- which may have affected 4000 people -- saying he was “deeply sorry” for those affected by its “serious wrongdoing”.

Yet just 48 hours earlier he tried to brush off the affair in an interview with his US title the Wall Street Journal, claiming that News Corp had handled the crisis “extremely well in every way possible”.

Further adverts will appear today and tomorrow outlining what NI and News Corp are doing to ensure the problems are not repeated.

It was reported last night that phones belonging to senior journalists on the Mail on Sunday may have been hacked.

The crisis began 13 days ago with the revelation that the News of the World hacked the phone of murdered schoolgirl Milly Dowler in 2002. Murdoch closed the tabloid within a week after claims that it also hacked the phones of relatives of terrorist victims and dead soldiers. But the scandal continued to spiral.

On Wednesday, with a newly emboldened House of Commons opposing his plans to buy the 61% of broadcaster BSkyB he doesn’t yet own, Murdoch was forced to shelve his £6 billion bid.

Murdoch apologised to Milly Dowler’s family on Friday. Brooks -- editor of the News of the World when Milly’s phone was hacked -- and Les Hinton, Murdoch’s right-hand man in America, left their jobs the same day as part of a clean-up. It was reported yesterday that Brooks’s severance package may amount to £3.5 million.

Hinton, chief executive of Dow Jones, the publisher of the Wall Street Journal, led NI during the period in which phones were being hacked. He has worked for Murdoch for more than 50 years, and was apparently fired to help contain the scandal in the US.

The exit of Brooks and Hinton leaves the Murdochs cast in the potentially fatal role of last men standing in the scandal. The position of James, 38, the heir-apparent to the family business, is particularly vulnerable as he signed off payments of more than £1m to celebrities whose phones were hacked. There was speculation last night that his sister Elisabeth may replace him.

Questions over what Rupert and James Murdoch knew about criminality at the News of the World, and when they knew it, will now dominate Tuesday’s meeting of the Commons Culture, Media and Sport Committee, when both men will give evidence alongside Brooks after being formally summonsed. Labour MPs on the committee will also grill James Murdoch about his meeting in January with Alex Salmond, and the Scottish Sun later backing the SNP in May’s election.

Labour last night published a list of 25 questions it said the SNP had to answer on its links with Murdoch and NI.

The Sunday Herald revealed the meeting last week, along with other SNP-Murdoch links including Salmond hosting a News of the World dinner at Bute House in 2009.

Labour’s business manager Paul Martin said: “Throughout the phone-hacking scandal Alex Salmond … has been uncharacteristically silent. He would clearly rather we all ignored the fact he met James Murdoch, wined and dined the editor of the Scottish News of the World and provided free articles and advertising to News International papers worth thousands of pounds.”

Before the Murdochs give evidence, the committee will also grill Sir Paul Stephenson over his failure to reveal Neil Wallis’s consultancy role with the Met.

It emerged yesterday that Paul McBride QC is to act for Bob Bird, the ex-editor of the Scottish News of the World, who gave evidence at Tommy Sheridan’s perjury trial last year, while the Crown Office re-examines evidence from the case.

An SNP spokeswoman described Labour’s list of questions about links to the Murdochs as “embarrassing nonsense”, given that the First Minister called last week for Brooks to quit and supported the Commons motion against the BSkyB bid.