The City watchdog has said it is "highly unlikely" that a report into RBS's mistreatment of small businesses will be published before a deadline imposed by MPs, but it has agreed to send them a copy.
Earlier this week Andrew Bailey, head of the Financial Conduct Authority (FCA), was ordered by Treasury Select Committee chair Nicky Morgan to release its report into GRG, the lender's controversial restructuring arm.
But on Friday Mr Bailey wrote to the MP saying that "legal impediments" make it improbable that the FCA will be able to publish before the February 16 deadline.
The legal hurdles include having to obtain the consent of "all persons from whom information was obtained" and "to whom the information relates".
The law also requires the watchdog to give anyone criticised in the report a "fair opportunity to respond" prior to publication, the FCA said.
While Mr Bailey said that the FCA will write to those named in the report to get consent and to offer them the right to respond to criticisms made, it is unlikely these will be obtained before the deadline.
"Given these legal impediments to which we are subject, we think it is highly unlikely that it will be possible for the FCA to publish the report by 16 February," his letter read.
However, he added that the FCA will hand over a copy to Mrs Morgan by February 16.
Mrs Morgan said in response: "I am pleased to see that the FCA is trying to get the report agreed for publication or handed to the Committee to meet its deadline."
The watchdog chief again cautioned the MPs against publishing the report themselves using their Parliamentary privilege.
"If the committee decides itself to publish the report, it will no doubt want to consider carefully the precedent of publishing a document obtained from the FCA under Parliamentary Privilege where the FCA considers that it is legally constrained from publishing the document itself."
The exchange comes following Mr Bailey's hours-long grilling by the influential committee on Wednesday, in which the taxpayer-owned bank's shortcomings were again under the spotlight.
RBS has been dogged by allegations that GRG intentionally pushed small businesses towards failure in the hope of picking up their assets on the cheap.