Image caption Rupert Murdoch spoke to staff in the newsroom

Rupert Murdoch has told staff at the Sun newspaper in London he will launch the Sun on Sunday tabloid "very soon".

The News Corporation boss, 81, offered his support to Sun journalists at News International's offices in Wapping.

Ten current and former senior staff at the paper have been arrested since November in connection with alleged corrupt payments to public officials.

Mr Murdoch lifted all staff suspensions pending police inquiries, a move Labour MP Chris Bryant called "cynical".

The high-profile campaigner against and victim of phone hacking, said the decision to lift the suspensions was hypocritical.

"It is massively premature because one would have thought the Murdoch empire would want to wait until Leveson had completed his inquiry and the police and prosecuting authorities had completed their investigations," he said.

"News International has tirelessly campaigned for people who have been charged to be suspended from public office and yet journalists who have been charged at News International are apparently not going to be suspended."

Analysis Rupert Murdoch's decision to go ahead with the Sun on Sunday is a typically bold move, designed to restore journalists' morale and regain the initiative, but many uncertainties remain. It was widely believed that the replacement for the News of the World had been suspended indefinitely after the fallout from the phone-hacking scandal spread to other Murdoch papers. The arrest of so many senior Sun journalists seemed to make the launch of a seventh-day Sun impractical. And the American parent company News Corp was known to be disenchanted with the UK newspaper business. Will it really want to invest more money in it at a time of such legal and financial uncertainty?

Mr Bryant was awarded £30,000 in damages after his phone was hacked by the now defunct News of the World (NoW). Lord Justice Leveson's ongoing inquiry is examining press standards and ethics.

It has been suggested that the bail conditions of the arrested Sun journalists might prevent them from returning to work, but a News International spokeswoman confirmed there were no conditions affecting the staff.

Mr Murdoch arrived on a private plane at Luton Airport from the US on Thursday evening and was taken to Wapping in a vehicle with blacked-out windows.

The meeting followed anger at the way in which the News Corporation's management and standards committee - set up to investigate allegations of wrongdoing - passed on information to the police.

But Labour Leader Ed Miliband said it was right that News International had provided evidence to the police that led to the arrests.

"Of course News International should be co-operating with the police. There is some evidence - some allegations anyway - of criminal activity," he told BBC Radio 5 live.

Media playback is unsupported on your device Media caption Chris Bryant MP: "The cynicism with which Rupert Murdoch is treating the British public is pretty despicable"

If the company had co-operated with police years ago, we would not be in "this mess", he added.

'Huge mistake'

In an email to staff, Mr Murdoch said: "We will build on the Sun's proud heritage by launching the Sun on Sunday very soon.

"Having a winning paper is the best answer to our critics."

He said he would stay in London for the next several weeks but, describing the recent arrests as a "great source of pain", warned: "Illegal activities simply cannot and will not be tolerated".

But Mr Murdoch praised the "superb work" of Sun journalists and said "the Sun is a part of me".

The company was doing everything it could to assist those who had been arrested, his email said.

"News Corporation will cover their legal expenses. Everyone is innocent unless proven otherwise," it said.

A middle-ranking News International journalist told the BBC the mood amongst colleagues was "chaos in a good and bad way. Mainly good actually. People really happy at fighting talk".

Image caption Demonstrators protest outside News International's Wapping offices in east London

Last year News Corporation closed the NoW over impropriety.

Revelations that staff employed by the newspaper hacked the phones of public figures prompted the closure of the 168-year-old publication.

The National Union of Journalists has said news organisations have a duty to protect their sources, and is considering a legal challenge to the company.

General secretary Michelle Stanistreet (NUJ) told the BBC Mr Murdoch could have stemmed the "huge anger and frustration" by calling off the committee and acknowledging its action had been a "huge mistake".

"It's done a huge disservice to press freedom because we have a situation now where confidential sources have been betrayed... it's been handled so badly," she said.

Media commentator Steve Hewlett said Mr Murdoch was facing the kind of "ructions" in his company he had never seen before.

"What he's trying to say to the people here is 'look we really are on the same side', but the fact is he is between a rock and a hard place and these are both of his and his company's own making," he said.