Barclays chief Bob Diamond said the bank had not met "the high standards that we set for ourselves" in the wake of a rate-rigging scandal that could cost the industry billions of pounds.
In a letter to Andrew Tyrie, the chairman of the Commons Treasury Select Committee, Diamond accepted Mr Tyrie's demand that he attend a session of the Committee.
The letter said: "I am writing to let you know that I would be happy to attend such a session. I appreciate that the nature of the settlements disclosed yesterday raises many questions, and I welcome the opportunity to provide answers to those for the Treasury Committee. My office stands ready to work with the Committee Clerk to facilitate that at your convenience.
Bob Diamond, the chief executive of Barclays has agreed to answer questions at the Treasury Committee
"As you know, our settlements yesterday represent only a part of a complex, industry-wide investigation by authorities that include the US Department of Justice, Fraud Section, US Department of Justice, Antitrust Division, the U.S. Commodities Futures Trading Commission and the Financial Services Authority.
"Barclays is the first bank to settle with those authorities. That settlement is the result of several years of work that involved close cooperation between Barclays and the DoJ, CFTC and FSA. As a result, the findings are extremely detailed. But the principal message is simple: Barclays actions did not meet the high standards that we set for ourselves."
The Treasury has started to look at strengthening criminal sanctions for those responsible for market abuse after Barclays was fined £290 million by UK and US regulators for manipulating the rate at which banks lend to each other.
HSBC and taxpayer-backed Royal Bank of Scotland are among several other lenders being investigated by the City watchdog for fixing the interbank lending figures that affect millions of homeowners and small firms.
Serious Fraud Office investigators are in talks with the Financial Services Authority (FSA) over the scandal while pressure is mounting on Barclays chief executive Bob Diamond to stand down.
Barclays saw shares slide 15% - wiping £3 billion from its market value - as investors ditched the stock amid fears the fines could be dwarfed by lawsuits and damages.
The banking sector is expected to remain firmly in the spotlight tomorrow when the Financial Services Authority (FSA) discloses it has found evidence of mis-selling of complex financial products call interest rate swaps to small businesses.
Chancellor George Osborne told MPs the rate-rigging scandal was "a shocking indictment of the culture of banks like Barclays in the run-up to the financial crisis".
The Chancellor issued a stern warning to the bank over its conduct
Turning to Mr Diamond, who waived his bonus for 2012 in light of the scandal, the Chancellor said: "As far as the chief executive of Barclays is concerned, he has some very serious questions to answer today.
"What did he know and when did he know it? Who in the Barclays' management was involved and who, therefore, should pay the price?"
The controversy, which covers a period between 2005 and 2009, could spread to other lenders, as RBS, HSBC, UBS and Citigroup are also being investigated.
The penalties, including a record £59.5 million fine from the FSA, followed claims that Barclays manipulated the Libor - London interbank offered rate - and Euribor interbank lending rates.
The rates are set on wholesale money markets - where banks lend to each other - which in turn affects rates they pass on to customers through credit cards, loans and mortgages.
The British Bankers' Association (BBA) launched a review into Libor and how it was set in March. In a statement, the BBA said: "As part of this review we will now be asking the authorities to consider in what manner the Libor-setting mechanism should be regulated in the future."
The Chancellor confirmed the government was already looking at Libor regulation in the context of wider financial services reforms and would consider changing the law so that bank fines go back to the taxpayer.
In the depths of the financial crisis, Barclays gave false information about the interest rates it had to pay to borrow money to paint a false picture of its health to markets.
Mr Diamond, who was in charge of Barclays Capital at the time the breaches occurred, apologised and said nothing was more important to him than "having a strong culture at Barclays".
READ MORE:
- Chancellor Warns Those Behind Libor Scandal Unlikely To Face Charges
- Barclays Has 'Serious Questions To Answer', Says David Cameron
- Barclays Should Face 'Criminal Investigation', Says Miliband
- Could More Banks Be Caught Up In The Lending Rates Scandal?
- Barclays Lending Rate Scandal: Emails Reveal Suspicious Behaviour Of Staff
Senior executives Jerry del Missier, Rich Ricci and chief financial officer Chris Lucas will also waive their 2012 bonuses.
A trail of emails, instant messages and phone transcripts disclosed by the FSA showed how traders requested Barclays make changes to the Libor rate to boost their profits.
Mr Osborne said the communications "read like an epitaph to an age of irresponsibility".
In one request for a change to the Libor rate, a trader said: "Coffees will be coming your way either way, just to say thank you for your help in the past few weeks". To which the Barclays' submitter responded: "Done, for you big boy."
The scandal is another blow to the beleaguered banking sector as it battles to restore its tarnished image in the wake of the financial crisis, the scandal of mis-sold payment protection insurance (PPI) and the computer problems at RBS which froze millions out of their accounts.
Sandy Chen, banking analyst at Cenkos Securities, said he was braced for billions of pounds in fines and damages across the banking sector.
He said: "We are pencilling in multi-year provisions that could run into the billions."
The pressure will mount tomorrow when the FSA is expected to disclose that it has found evidence that businesses were sold complex interest rate swaps without fully grasping the downside risks.
The swaps are complicated derivatives products that may have been sold as protection - or to act as a hedge - against a rise in interest rates.
Barclays is the first major financial institution to settle with regulators over Libor rigging following a wide-ranging investigation that has spanned North America and Europe.