Binyam Mohamed's action against MI5 and MI6 is the sort of embarrassment green paper aims to prevent if it becomes law
Introducing secret hearings into civil courts could backfire, leading to more claimants accessing sensitive information, according to the government's own impact assessment of its justice and security green paper.
Expanding the use of so-called "closed material proceedings" (CMPs) may also result in jurors finding the vetting procedure intrusive, and in "resentment of the judicial process and unwillingness to participate in jury service", the Ministry of Justice's study warns.
The highly critical comments are buried deep in the department's own appraisal of the measures, which are intended to protect national security. They are in sharp contrast to the upbeat public endorsement given by the justice secretary, Ken Clarke.
When he presented the green paper to parliament, Clarke declared: "[We] seek to produce a system whereby our public and our allies can be reassured that these matters will be handled sensitively in this country. People will share intelligence with us knowing that it will be used properly, will not be misused and will not be disclosed in areas where it would do damage."
But the MoJ's less widely circulated impact assessment cautions that there is a "higher risk of potential security breaches due to a larger number of individuals accessing sensitive information … [and] any potential breaches may impose substantial costs to UK security".
Clarke is to appear before parliament's joint committee on human rights on Tuesday to face questions about the proposals, which go far beyond the existing public interest immunity certificates used in cases involving MI5, MI6 or Special Branch.
The civil liberties group Reprieve, which has campaigned on behalf of detainees who have been secretly "rendered" to overseas prisons, highlighted the critical comments in the impact assessment document. It has accused the government of "sleepwalking into a system of secret courts". British courts are already well equipped to deal with national security cases, it insists. "To claim otherwise is to allow our government's addiction to secrecy to erode centuries-old traditions of open justice."
The justice and security green paper is aimed at closing down embarrassing public actions brought against the intelligence agencies by former terrorist suspects such as Binyam Mohamed, a British citizen held in Guantánamo Bay, who claimed he was tortured while detained in jails, including in US custody.
Under the proposals, not only would ministers be able to order a hearing to be conducted in secret, but the proceedings would also deny claimants access to government evidence or witnesses – leaving them effectively untested in court. In addition, the final judgment could be wholly or partially withheld.
There have been 90 submissions in response to the green paper, of which 77 have been published on the Cabinet Office website. Among the latest releases is the response of the Police Federation, which warns that CMPs should be used only in "exceptional cases". It adds: "There is clearly a disadvantage to excluded individuals from CMPs, and a risk to the interests of justice."
But a number of the organisations, including several police forces, appear reluctant to reveal their comments . Lancashire, Kent and Essex Police have been asked, on a number of occasions, to make their submissions public, but have failed to respond.
A spokesman for the Cabinet Office said: "In the interests of ensuring maximum transparency, we are actively seeking consent to publish as many responses as possible. Even in cases where consent is withheld we are proposing to publish a summary that reflects the full range of responses received. Separately, a very small number of responses were submitted in confidence. The government is under a legal duty to respect that."
Of the remaining unpublished submissions, seven are individual members of the public, three are police or law-enforcement bodies, two are private companies and one is a public oversight body.
Among others to voice concern about the proposals is the former director of public prosecutions Lord Macdonald. He warned earlier this week: "These unprecedented proposals are an audacious attack on the fundamental principle of British justice: that you should be able to know, and to challenge, the claims which are made against you."
"They threaten to put the government above the law, while leaving ordinary citizens, and the press, shut out of their own justice system. After a decade in which we have seen our politicians and officials caught up in the woeful abuses of the War on Terror, the last thing the Government should be seeking is to sweep all of this under the carpet. However, that is exactly what their disastrous secret justice proposals are likely to do.
"David Cameron came to power saying 'sunlight is the best disinfectant'. We should not sacrifice Britain's open and transparent justice system simply to protect politicians and their officials from embarrassment."