UK politicians have hired a barrister to check if a summary of a report by regulators into how Royal Bank of Scotland treated companies in difficulties is comprehensive and fair. 

The Financial Conduct Authority has refused to publish the main report, saying it was never meant to be public and that a summary would be made available. 

But in a sign of how politicans are losing patience with the watchdog, the Treasury Select Committee has appointed barrister Andrew Green to check by October 27 if the FCA's summary closely reflects the main report. 

"On receiving the adviser's assessment, the committee would decide how to proceed, and the arrangement would be without prejudice to its formal powers to require that the FCA produce the report," TSC Chair Nicky Morgan said in a letter to FCA CEO Andrew Bailey and released to the media. 

"The committee wants the maximum possible transparency to be brought to this long-standing issue," Morgan said. 

"In any case, the long-awaited summary should be published as soon as possible. The committee's review is not a reason for further delays," she added.

RBS's Global Restructuring Group handled 12,000 troubled firms between 2007 and 2012, and has been accused by customers of pushing some of them into bankruptcy in order to pick up assets on the cheap. 

RBS, which owns Ulster Bank here, has admitted some wrongdoing over its handling of small businesses, but has said there was no evidence it pushed companies into bankruptcy.

The FCA said today it has already asked an independent external counsel to confirm that the watchdog's summary is a fair and balanced account of the full report's findings. 

"We welcome further dialogue with the TSC on providing assurance about the publication of the summary," the FCA said. 

The full report is based on a so-called skilled persons report conducted by Promontory consultancy in 2014. 

The FCA has said that reports of this kind were compiled on the understanding they won't be published. 

But Morgan said today the GRG report is an "exceptional case", given that is has already been leaked and reported by the BBC. 

She will quiz Bailey in public when he appears before her committee in the coming weeks.