Like many, I favour a judge-led inquiry into the banks fiasco. But what could it realistically achieve?

Poor parliament. Its powers stripped by the European Union, the courts and the devolved assemblies. Its proceedings controlled by the executive. Its members so mocked by the media and the public it appears that the British loathe the sight of their politicians, and wish only for an escape from representative democracy.

As soon as a crisis begins, the cry goes up for an outside agency to take charge: for the unelected officials of the Bank of England to acquire more powers; for the Office for Budget Responsibility to deliver accounts of the national debt politicians cannot be trusted to provide. As soon as a scandal emerges, offended parties call for lawyers to hold “independent” inquiries and judicial reviews.

Bob Diamond’s condescension to the Treasury select committee demonstrated the ignominy into which parliament has fallen. Diamond would never have dared address a judge by his or her first name. But the gilded banker felt no qualms about calling the gelded members “Jesse”, “Andrea”, “Michael”, “David” and “Andy”. If he had been before a judge, Diamond – or should that be “Bob” or maybe “Bobby”? – would have made sure that his evidence was beyond reproach.

As it was, when Andrew Tyrie, the committee chairman, asked: “Is it true the FSA [Financial Services Authority] was concerned about your appointment as chief executive and sought assurances there would be a change of culture?” Diamond replied: “I got very strong support for my appointment to chief executive.” Maybe the £120m he pocketed between 2005 and 2012 clouded his memory, but letters from the FSA in Tyrie’s possession showed that it was concerned about Diamond’s promotion and wanted assurances from the Barclays board that its aggressive culture would change.

Add in the sight of George Osborne and Ed Balls turning the ruin of the hopes of millions into an excuse to abuse each other, and the case against parliament seems complete.

But you cannot escape politics, nor should you want to. Although, like many others, I want a judge to investigate the worst riot of capitalism since 1929, I know that the history of judicial investigations into politically sensitive scandals is mixed. They are like psychoanalysis: the process is revealing, but the conclusions are banal.

The evidence to the Leveson inquiry produced an exposé that tabloid journalism will never live down. But if you imagine that Lord Justice Leveson’s findings will force Jeremy Hunt to resign, remember the dashed expectations of all those who thought that Lord Justice Hutton’s inquiry into the Iraq war would force the resignations or Tony Blair and Geoff Hoon.

Or consider Lord Franks’s report on the Falklands war of 1982. The judge itemised all the blunders that allowed the Argentinian junta to invade. But he could not bring himself to hold a single minister responsible in his concluding comments. “For 338 paragraphs he painted a splendid picture, delineated the light and the shade, and the glowing colours in it,” said James Callaghan in the Commons debate on the Franks report. But “when Franks got to paragraph 339 he got fed up with the canvas he was painting, and chucked a bucket of whitewash over it”.

When they sit alone in their study, investigating judges must wonder what right they have to bring down politicians. Britain is a democracy, not a judgocracy. It is the job of MPs to end the career of ministers. If they do not, the voters can remove them at an election. Who are judges to interfere?

I have no way of knowing whether Leveson will break with tradition by forcing Hunt out, or instead apply the customary coat of whitewash. But there is a second restriction on “independent” inquiries he is already observing. If an investigating judge wants to change the law, he has to persuade the despised politicians to change it for him. During the Leveson inquiry, there was a telling, and alarming, moment when the judge explained to Michael Gove his plans for a new press regulator. Membership would be voluntary, but if a newspaper refused to join, the courts might hit it with “exemplary damages”, he said, because the paper could have had the libel or privacy action resolved “very easily” under the Leveson system.

The journalists he imagined defying him and receiving “exemplary” punishment were not the Peeping Toms of the tabloids but the staff of Private Eye, who expose corruption in the City, media, government and the law rather than find pleasure from making Sienna Miller cry. I had forgotten, until Leveson reminded me, that the legal establishment has always been the enemy of serious journalism. I was as struck by the judge’s reaction to Gove’s reply. The minister implied that Leveson was 30 years behind the times. Every web page was now a newspaper. Everyone who wrote online was now a journalist. Were all of them to submit to the judge’s new regulator or face “exemplary” punishments? A truculent note entered Leveson’s voice as Gove contradicted him. He realised that for his controls to work, politicians must approve them, and the politician in front of him would not.

People who hate all politicians end up hating themselves. By all means hate this minister or that party, but remember the difference between politicians and judges, journalists, bankers and European commissioners. The electorate can remove its elected representatives. Say that power does not matter because “they’re all the same” or “only in it for themselves” and you are denying the possibility of democratic renewal.

In their small way, the Commons select committees have been making the possible real. The public accounts committee (PAC) has responded to the crisis by pushing the permanent secretary at Revenue & Customs into taking early retirement because of his sweetheart deals with the vulture capitalists of Goldman Sachs.

The PAC and the other parliamentary committees could do much more, but they need help. The American equivalent of the PAC has 120 staff. A British committee is lucky to have just one clerk. Those who would deny our representatives resources because they think that all politicians are crooks are only serving the interests of Bob Diamond and his kind.

Leaving all other considerations aside, the prime minister establishes “independent” public inquiries, while select committees are free to examine what they will. When the prime minister refuses to initiate a judicial investigation into the banking scandal or any other scandal, we are where we always have been: stuck with parliament. A poor thing, but our own.

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