A new report claims RBS should be broken up into 130 locally-run banks when the government sells out.
The New Economics Foundation says if the policy had been implemented in 2008, an extra £10billion a year would have flowed into the UK economy.
The report by the left-of-centre think tank, published ahead of the bank reporting its results tomorrow, says there is "strong international evidence to support a public trust model of ownership" on the John Lewis model.
It says: "From the Royal Bank of Cornwall to Royal Bank of Bradford, the majority of new banks would have total assets of between £1-2bn, tapping into existing local identities and better serving the needs of regional economies.
"Nationally, the resulting boost to GDP would far outstrip the estimated £700m annual savings in interest payments that would result from using the estimated £40bn proceeds from privatisation to repay national debt."
RBS has received more than £45bn in public funds since it was bailed out in 2008, and the government retains an 80per cent stake.
Chancellor George Osborne reaffirmed the government's intention to privatise the bank in his 2013 Mansion House speech.
The NEF says the local model would increase lending to SMEs, improve the diversity and resilience of the UK banking system by protecting against future economic shocks, promote financial inclusion by reversing the trend of branch closures, and rebalance the economy by boosting regions outside London.
It claims a "mutual guarantee scheme", and the combining of central and back office functions, would ensure both financial stability and efficiency.
The NEF's Tony Greenham said: "Regardless of the bank's performance this week, a hasty sell-off is not in the public interest."
Meanwhile RBS has not disputed a report that it is putting Rory Cullinan in charge of overseeing another scaling back of its investment bank.
Mr Cullinan, who already runs the internal 'bad bank' and is overseeing the disposal of its Citizens and Williams & Glyns businesses, will take over responsibility for RBS's investment bank from Donald Workman, currently executive chairman for corporate and institutional banking.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article