Marcus Agius has confirmed he will resign as chairman of Barclays following the inter-bank lending rate-fixing scandal.
In his statement, Mr Agius said: he was "truly sorry" and that "the buck stops with me".
Last week Barclays was fined £290m ($450m) for attempting to manipulate the Libor inter-bank lending rate.
Barclays' chief executive Bob Diamond will appear before the House of Commons Treasury Select Committee on Wednesday.
Mr Agius is due to answer their questions on Thursday.
Barclays said Mr Agius would remain in his post until "an orderly succession is assured".
Sir Michael Rake, BT chairman and senior independent director at Barclays, has been appointed deputy chairman at the bank.
Sir John Sunderland, a non-executive director of Barclays, will begin the search for a new chairman from Monday.
Barclays was fined after the Financial Services Authority (FSA) found its traders had lied about the interest rate other banks were charging it for loans.
Investigations are also under way at RBS, HSBC, Citigroup and UBS.
Giving a lower reading than the true rate would give the impression that Barclays was considered a better lending risk than it actually was.
Libor (London Inter Bank Offered Rate) is the rate at which banks in London lend money to each other.
Mr Agius said last week's events were evidence of "unacceptable standards of behaviour within the bank".
He said the findings had "dealt a devastating blow" to Barclays' reputation.
As a result Barclays' board has launched an audit of its business practices, which will be conducted by an independent body and report to the new deputy chairman, Sir Michael Rake.