London (CNN) -- Former Barclays CEO Bob Diamond has hit back at British lawmakers who suggested he misled them over concerns voiced by the country's financial regulators.
CNN can also reveal that those very same regulators will now be called to testify next week alongside a key Barclays executive, who Diamond said had mistakenly told traders to lower their submissions to the London Interbank Offered Rate -- or Libor.
Adair Turner, chairman of the Financial Services Authority watchdog, has been been called to the Treasury Select Committee Monday afternoon with the head of the FSA's bank supervisory body Andrew Bailey, the man famous for warning Barclays of failings in its culture.
Turner and Bailey will appear after panel members take a pre-arranged briefing from the Bank of England Governor Mervyn King.
Officially King is slated to present the central bank's quarterly update on the UK economy and interest rates. However, sources say the discussions are likely to focus heavily on the issue of Libor after King's deputy Paul Tucker refuted suggestions he leaned on Barclays to lower its rate submissions.
Jerry Del Missier, former Barclays Chief Operating Officer, will also give evidence Monday, in what is likely to be the most keenly watched testimony of all.
Diamond's right-hand man also quit last week after the bank was fined a record £290 million (US$449 million) for fixing the interest rate floor upon which trillions of dollars worth of financial contracts are based.
Del Missier will come in for questioning about claims he misread an email from Diamond asking him to lower Libor submissions following a conversation between Diamond and Tucker.
Questions also remain about whether or not Diamond was aware of correspondence between the FSA and Barclays about the bank's alleged use of financial structures "at the aggressive end of interpretation of the relevant rules."
At the time of writing, four out of the 13 lawmakers on the committee charged with investigating the Libor scandal said they would like to see Diamond be recalled to clarify his earlier statements.
In a letter obtained by CNN from Diamond to UK Treasury Select Committee Chairman Andrew Tyrie dated July 10, the 60-year-old American-born banker seemed keen to get a second chance to speak.
Diamond said the comments made at the hearing had had "a terribly unfair impact" upon his reputation, a reputation which Diamond said was "of paramount concern to me."
He added: 'I look forward to discussing this issue with you further if you wish to do so."
Yet those close to the parliamentary body say it is unlikely Diamond will have a second chance to put on a polished appearance because the committee is due to be reshuffled next week.
"It's not the complexities of this that are the problem. It's the evidence that's the problem," said one unnamed member.
"Also time is working against us."
Another doubted Diamond would become embroiled in the Serious Fraud Office's recently launched Libor probe, even if sources at Barclays confirmed to CNN they are bound by Diamond's contract to cover his legal costs, should he face any.
All the while Diamond has waived his right to £20 million (US$31 million) in deferred compensation and bonus payments, walking away instead with a tenth of that amount.
John Mann MP, a lawmaker and member of the committee that interrogated Diamond last week, said: "You only give up your job and your pay if you've got no cards to play.
"This has never been how Bob Diamond has ever operated."
Bob E. Diamond Jr's letter to Treasury Select Committee Chairman Andrew Tyrie
July 10, 2012
Dear Mr Tyrie,
Having watched the Committee's session today I was dismayed that you and some of your fellow Committee members appear to have suggested that I was less than candid with the Committee last week.
Any such suggestion would be totally unfair and unfounded.
The focus of your concern appears to relate to correspondence between Messrs. Turner and Agius in April 2012. The questions asked of me, however, concerned the period of promotion in September 2010 and the board meeting I attended in February 2012.
As the letters of April 2012 make clear, those letters followed an April meeting between Messrs. Turner and Agius, which I did not attend. I was not asked about the April 2012 meeting nor was I asked about, nor shown, the follow up letter to that April meeting at our session.
I trust this addresses any concerns you may have had.
The comments made at today's hearing have had a terribly unfair impact upon my reputation, which is of paramount concern to me.
I look forward to discussing this issue with you further if you wish to do so.
B. Diamond (signature)