As the Guardian has reported, a proposal to call the former HSBC boss and Conservative minister Lord Green to appear before parliament has been blocked by Tory MPs.

I’m constantly amazed, as the HSBC banking horror story unfurls, to discover how many people at the top were paid so much to not know what was going on. It’s even more amazing to find that they face no sanction at all, beyond the embarrassment of appearing before parliamentary select committees to justify the way they’ve profited from turning a blind eye to what amounts to criminality.

It is vital, to maintain the credibility of both the banking and the tax system, that wrongdoing should be exposed and punished, and that those responsible should not profit from it. In the United States, with its tougher regulation, perpetrators face consequences. So in 2012 HSBC was fined $1.9bn (£1.25bn) because its “blatant failure to implement proper anti-money laundering controls facilitated the laundering of at least $881m in drug proceeds”, and the bank “accepted responsibility for its criminal conduct and that of its employees”.

Here in Britain we’re much nicer. Chaps rule and regulate other chaps, while HM Revenue and Customs tries to maintain good relations with the big corporations. So when yet another HSBC scandal was forced on the reluctant attention of our regulators, with the leaking by Hervé Falciani of a list of clients of HSBC’s private bank in Switzerland who had been using Swiss accounts to evade tax with the active support of the bank, the matter was handed to the revenue – not to the courts or the regulators.

The bank profited from criminality. The directors, on bonuses and profit-related pay, benefited. Yet no director, non-executive director, audit committee member, or auditor fulfilled even the minor responsibility given them under the corporate governance codes to “comply or explain”, and none of them brought matters to public attention. No one at the bank has suffered any sanctions.

Lord Green – the man who was chief executive from 2003 to 2006, then chairman from 2006 to 2010, and therefore in charge of the whole operation – hasn’t even had to suffer a tongue lashing from Margaret Hodge, the chair of the public accounts committee, on which I also sit. He was put into the Lords and made a minister by David Cameron when he retired from the bank. Tory members of the public accounts and the treasury committees don’t want him to appear (neither do some Labour members). The government clearly doesn’t want him grilled. I’d guess that if he did have the decency to fulfil his responsibilities and explain his position, Lord Green would use the same excuse as those HSBC executives who have faced up to a select committee grilling, which is to say: “I might have drawn big money and bonuses for being in charge but I certainly didn’t know what was going on. Someone should have told me but no one did.”

Directors have a responsibility under the 2006 Companies Act to discharge their fiduciary duties towards the company. They must not evade this. So at HSBC, either directors were drawing huge amounts of pay for doing nothing – in which case they are being paid under false pretences – or the bank was too big to manage and should be broken up.

It’s also perfectly possible that HSBC was not a unique case and that other banks were doing much the same things. We do need to know, and the only way to restore faith in the system now would be for Lord Green to have the integrity to explain his role. Both he and the others who ran HSBC but failed so badly to fulfil their responsibilities to customers, shareholders and the law should face meaningful sanctions rather than well-upholstered retirements.