Unrepentant Clarke backs 'kafka' trials

The Minister Without Portfolio, who retains responsibility for the controversial Justice and Security Bill, attempted to play down widespread criticism of the plans at a think tank Policy Exchange meeting.

He claimed that civil liberties groups who oppose the reforms must choose "between scuppering a golden opportunity for reform or making the security services more accountable."

It is "decision time for us civil libertarians," he said.

"Some appear to be saying that if spies cannot give evidence in open court then they prefer to stay with secrecy and exclusion of evidence.

"Serious cases involving allegations of torture should be undecided, the amount of damages settled by a silenced defence.

"Others appear to have taken the debate into the realms of fantasy."

Under the plans, in cases deemed to be matters of "national security" the government and security forces could submit evidence which the claimant and their legal representatives would not be able to hear.

Instead, special advocates would be appointed who could hear the evidence on the claimant's behalf, but not share it with them.

Mr Clarke claimed that the final decision would be in the hands of the judges but the special advocates themselves and the government's reviewer of terrorism legislation have warned the plans lack key safeguards and would create a statutory straitjacket for judges.

The Bill is a direct result of a civil claim brought by 16 former Guantanamo detainess, including Binyam Mohamed, who alleged British complicity in their kidnap and torture. The government was forced to settle that case in 2010 to prevent further details of complicity from emerging in open court.

It claimed it was wasting millions of pounds of taxpayers' money on settling such claims because it was unable to contest them as the evidence it would wish to produce is so secret that it cannot be revealed in an open court.

But critics argued that current provisions make this perfectly possible and that the government was merely attempting to prevent embarrassing details of its complicity in torture from emerging.

Reprieve executive director Clare Algar said: "Nothing Ken Clarke said today justified the government's dangerous plans for secret courts, which will allow ministers to cover up embarassment or even serious crimes such as torture. His reassuring comments do nothing to change the reality of the Bill itself, which would put politicians above the law and deny ordinary citizens access to justice."

And civil rights group Liberty director Shami Chakrabarti said the Bill would "replace open courts with secret stitch-ups between the government and judges, with the victims, press and public shut outside."

"Have we still not learned the danger of cover-ups?

"This Bill only undermines trust in both security and justice itself," she said.