In the Q&A session following his speech [2] on policing this morning, Ed Miliband intensified the pressure on Conservative trade minister Stephen Green, who was head of HSBC [3] at the time of the money laundering scandal. He called for Green to answer questions in the House of Lords (he sits as a Tory peer) on what he knew about the affair, which saw the bank used as a conduit for "drug kingpins and rogue nations".

"What happened at HSBC is frankly shocking," Miliband said.

In a similar vein, a leader in today's Times [4] (£) notes that "It would be interesting to hear from Lord Green, a man who has great personal integrity and a strong ethical code, an account of how things at the bank went awry. The issues at stake here go beyond the role banks play in the economy to the role they play in society. Do they facilitate or inhibit crime? Do they enhance or undermine international security?"

But Downing Street is insistent that Green's position is safe. One source told the Telegraph [5]: "As far as we are concerned, he’s not going anywhere – there are no allegations against him and all this information was already in the public domain."

But emails released by US senators as part of their investigation into HSBC show that Green was kept informed by the bank's then compliance chief David Bagley. In 2005, he was told there was "little doubt" that a transaction from Burma breached US government sanctions, raising the prospect of "a significant risk of financial penalty".

David Cameron may feel that the government can continue to brush aside questions on the subject, but as his handling of Andy Coulson and Lord Ashcroft showed, he has a tendency to underestimate scandal.