There is no reason for Lord Green of Hurstpierpoint, the trade minister, to answer questions in the House of Lords over his role as head of HSBC while the bank's subsidiaries were alleged to have been involved in money laundering, peers have been told.
Lord Strathclyde, the leader of the upper house, brushed off Labour requests for Green to answer questions on the grounds that he is not accountable to peers for his business career.
"There is no urgency in this matter," Strathclyde told peers. "The investigation started over two years ago. The report in question was published two weeks ago. There was no evidence of personal wrongdoing of [Lord Green]. Indeed there was no personal criticism of [Lord Green] whatsoever and the investigation is ongoing.
"As for ministerial accountability, he is accountable to this house for the work he does as a minister. But we have had many ministers who've had previous careers. No minister needs to be accountable to parliament for his previous career, only for what they are doing as ministers."
Labour has been demanding that Green appear before peers after a US senate committee found HSBC had ignored warnings that its global operations were being used by money launderers while the minister was running the bank. Green joined HSBC in 1982 and was its chief executive and then chairman between 2006-10.
Senator Carl Levin, chairman of the senate sub-committee, said: "In an age of international terrorism, drug violence in our streets and on our borders, and organised crime, stopping illicit money flows that support those atrocities is a national security imperative.
"HSBC used its US bank as a gateway into the US financial system for some HSBC affiliates around the world to provide US dollar services to clients while playing fast and loose with US banking rules."
Labour piled on the pressure by pointing out that Green had been invited to dinner by HSBC on 9 January this year. The dinner appears in a list of hospitality declared by ministers at the Department of Business.
Labour peer Clive Hollick tweeted: "If Lord Green, former chair of HSBC, is innocent and ignorant of money laundering why doesn't he just come to the chamber and say so?"
Lady Royall of Blaisdon, the Labour leader in the Lords, said Green should answer questions because the ministerial code says "ministers should be as open as possible" with parliament. "Would not such a move give Lord Green the opportunity to dispel once and for all the questions being asked about his present ministerial role," she asked.
But Lord Butler of Brockwell, a member of the HSBC board for a decade after his retirement as cabinet secretary in 1998, mounted a strong defence of Green.
He said: "While it may be the case that the chairman and chief executive officer of a major international company is accountable for everything that happens in that company, there is no possible way in which the chairman and chief executive can be responsible for everything that happens in a worldwide group of the size of HSBC."
Chris Leslie MP, the shadow financial secretary to the Treasury, said: "With his repeated refusals to answer questions about what he knew and when, Lord Green is treating Parliament and the public with contempt. He is not just a Minister in David Cameron's government, he is also an adviser to the Chancellor on banking issues and a member of the Cabinet Committee for banking reform. He must be accountable to Parliament."