Clive Stafford Smith: A stuffed toy can't stop prisoner abuse, Mr Howells

It is said that the very existence of the Security Services (SyS) involves violating, if not our own laws, the laws of other countries. We do not need to look at the excesses of the past eight years to know that, notwithstanding the best intentions of those involved. In a crisis, the temptation to sail close to the moral line and, often, across it, may prove too strong to resist.

It is for this reason that there must be strong, independent oversight of the SyS. It is hard to think of an area of government where such review is more important. When one describes the Intelligence and Security Committee (ISC), neither "strong" nor "independent" springs to mind.

First, the theory. Even the ISC selection process is problematic. It is comprised entirely of MPs, appointed by the prime minister. Since they review the actions of the government, there is something of the henhouse fox about it. Then there is the issue of who signs off on the ISC report: nothing may be made public unless the PM first vets it. Anything he considers inappropriate is redacted.

Practice provides no more comfort. After much hullabaloo, the Prime Minister promised on 19 March 2009 that there would be a new policy guiding how agents in the field should respond when they witness prisoner abuse. He said it would be published, after review by the ISC. Eight months later, Kim Howells replied to my enquiry that they had only just received the draft policy. I asked at once how much longer the process would take. Eleven weeks later I have had no response, and no policy has been forthcoming. One wonders whether the looming election has any bearing on this delay.

On 7 August 2009, I wrote to Howells pointing out aspects of the 2005 report that were wholly unsustainable, given the evidence that had since emerged in court. It was clear that the SyS had provided erroneous evidence to the ISC. Far from being unaware of American abusive interrogation, the SyS knew Binyam Mohamed was being mistreated from the start. SyS did not lose track of Binyam in February 2003 – it was still sending questions for the Americans to put to him more than a year later. SyS did not believe that Binyam was in US military custody; it knew (the judges' word) that he was in a black site. And so forth. I suggested that it might want to review and amend its report. I have never heard back.

On Friday, Howells took to the airwaves to savage Lord Neuberger for having the temerity to suggest that something was rotten at the Security Services. We should not prejudge the issues, said Howells. But as chairman of the "completely independent" and "completely objective" ISC, Howells assured the nation that he has seen all the classified evidence and the SyS has "no case to answer".

Well, five independent judges disagree. Even Howells's own government did not dispute that the SyS was "mixed up in the wrongdoing" of Binyam Mohamed's torture.

Howells leaves the Commons at this election, and I wish him well in his retirement. But he should never have been on the ISC, let alone its chair. He was a minister in the Foreign Office from 2005 until 2008, so he had a supervisory role over MI6 when the FCO was defending it (unsuccessfully) in court.

The ISC does not even qualify as a toothless tiger. It is, as best, Tigger, befuddled friend of Winnie the Pooh. Britain – and the Security Services – deserve more. It is time for a proper, robust supervisory body to ensure that the pressures of an inevitable crisis do not tempt us from our principles.

Clive Stafford Smith is director of the legal charity Reprieve