Murdoch tells revolting Wapping staff: 'I'm right behind you...'

Defiant tycoon declares that a Sunday edition of The Sun will be launched in Britain 'very soon'

Rupert Murdoch committed himself to continue publishing The Sun yesterday as he announced he would "very soon" launch a Sunday edition of Britain's biggest-selling daily newspaper.

Before undertaking a morale-boosting tour of the paper's newsroom, which was compared by staff to a "royal tour", the tycoon caused surprise by lifting the suspension of Sun journalists arrested as part of Scotland Yard's investigation into alleged bribery of public officials. "Everyone is innocent until proven otherwise," he said in an email.

The Independent has been told that The Sun will operate as a seven-day newspaper operation, rather than having a completely distinct staff for the new Sun on Sunday title. The launch of the paper will enable News International to take advantage of the lift in advertising revenues that will come ahead of the opening of the London Olympics in July. Mr Murdoch has been shown dummies of the new paper.

Mr Murdoch's bold gesture in lifting the suspensions has concerned detectives working on the Operation Weeting investigation into phone-hacking and Operation Elveden into bribery. Although the arrested Sun journalists are not forbidden from mixing with others under the conditions of their police bail, there is a fear that they will discuss police lines of inquiry with colleagues who might be arrested in future.

The move also raises questions as to the treatment of arrested former staff on the News of the World. One of those, the former chief reporter Neville Thurlbeck, tweeted: "Is this just a PR stunt and NOTW men don't matter as the paper is defunct?" In another anomaly, the former Sun features editor Matt Nixson has never been charged by the police over allegations relating to bribery of a public official and yet was fired by the company.

The National Union of Journalists, which called on Sun staff to join its ranks and help force union recognition, 26 years after the pivotal Wapping strike at News International, claimed that Mr Murdoch had acted because the recent arrests were "destroying the morale" of the company's journalists. Barry Fitzpatrick, the NUJ deputy general secretary, said that News Corp's Management and Standards Committee, which is working alongside the police, was "operating like a Star Chamber".

But the former Sun editor David Yelland applauded the actions of his former boss. "What a fantastic email to Sun staff from Rupert Murdoch," he said on Twitter. "So many friends, so many good journalists will be relieved."

'A proud heritage' - Murdoch's memo

I've worked alongside you for 43 years to build The Sun into one of the world's finest papers. It is...one of our proudest achievements...I have immense respect for...your exceptional journalism and, above all, you, the talented women and men who work tirelessly every day to ensure our readers have access to such a trusted news source...

We are doing everything we can to assist those who were arrested – all suspensions are hereby lifted until or whether charged and they are welcome to return to work. News Corporation will cover their legal expenses. Everyone is innocent unless proven otherwise...

We will continue to ensure that all appropriate steps are taken to protect legitimate journalistic sources... But we cannot protect people who have paid public officials.

We will build on The Sun's proud heritage by launching The Sun on Sunday very soon.