Ian Burrell: How far will Rupert Murdoch go to save the Currant Bun?

Is this the end of The Sun? Rupert Murdoch is reportedly flying to the UK, ostensibly to save a newspaper he has loved since he bought it in 1969 from being engulfed by an unprecedented police bribery scandal.

But as Tom Mockridge, the loyal Antipodean lieutenant he has placed in charge of his wobbling British newspaper empire, issued an assurance to The Sun's staff that the media mogul had a "total commitment" to continue publishing the paper, journalists on the tabloid were beginning to doubt it had a future.

The News of the World was shut down last July apparently to create a firewall that would protect the more lucrative brand of the daily sister paper from being burned by the phone-hacking scandal. Many News of the World evacuees were given refuge at The Sun.

But in recent months staff on the daily have felt anything but protected by News International (NI) and certainly not by the News Corp Management and Standards Committee (MSC), which is operating from separate offices within NI and has a remit to clean up the company's reputation. The MSC has made available to the Metropolitan Police a vast cache of internal emails which are being sifted carefully for words that might relate to criminal activity.

The Sun's journalists are scared. The shockwaves began in November with the arrest of the popular district reporter Jamie Pyatt, who was based in Windsor and known for his royal scoops. Then police arrested Cheryl Carter, The Sun's beauty editor and, more importantly, former executive personal assistant to ex-Sun editor and NI chief executive Rebekah Brooks.

By the end of January, raids had been carried out on the homes of four current and former members of The Sun staff: Mike Sullivan, the veteran crime reporter; head of news Chris Pharo; former deputy editor Fergus Shanahan; and former managing editor Graham Dudman. These were people at the very heart of The Sun's news operation.

The Sun has always been published with a swagger of self-confidence, from the days when Mr Murdoch put editor Larry Lamb in charge and changed it from a left-leaning publication to the home of Page Three girls. But there's not much confidence on the Currant Bun at the moment. Word quickly leaked back that the January raids had been no gentle knock on the door. Some of the searches took 13 hours and were carried out by teams of up to six officers, some of them highly experienced detectives seconded from elite squads.

Those arrested yesterday included a serving Surrey Police officer, a member of the armed forces and a Ministry of Defence employee. There were five Sun journalists among those held, all of them senior, including associate editor Geoff Webster, picture editor John Edwards, chief foreign correspondent Nick Parker and reporter John Sturgis. Most significantly from the point of view of The Sun newsroom, police arrested John Kay, the paper's multi-award winning chief reporter and a man revered by his colleagues. Kay, who is known for having excellent contacts in high places, is regarded as a model Sun reporter.

Dominic Mohan, The Sun's editor, appealed for calm and claimed, on the paper's day off, that his staff were focused on producing Monday's edition. Hardly. Mohan appeared before the Leveson inquiry and emerged fairly unscathed. Dummy editions were also recently produced of a Sun on Sunday newspaper which NI had hoped to launch as a replacement for the News of the World. The arrests surely mean there is no prospect of that happening now.

Even if Mr Murdoch flies in, it is not clear just what he could do to help his stricken paper. But with News Corp releasing financial figures last week showing that the phone-hacking scandal has cost the business £126m already, he will come under great pressure to withdraw from a sector that contributes very little to his global media empire and has become a severe embarrassment.

The Sun, then, could go the way of the News of the World. Except that there are options. Waiting in the wings, should Mr Murdoch decide to sell, are other magnates – most notably Richard Desmond, who has previously expressed interest in getting his hands on The Sun.