Exclusive: David Miliband: Britain was slow to act against US torture

Critics of Labour leadership frontrunner accuse him of 'burying his head in the sand' over abuses

The United States did "bad things" to terror suspects in the wake of 9/11 which Britain was too slow to realise, David Miliband acknowledges today as he brandishes his record as Foreign Secretary to bolster his Labour leadership ambitions.

In an exclusive interview with The Independent on Sunday, the contest's frontrunner speaks bluntly about both the behaviour of Britain's closest intelligence ally and the failings of his predecessors at the Foreign Office in not recognising sooner the US's unacceptable treatment of detainees.

Reaffirming his commitment to an "ethical foreign policy", Mr Miliband's remarks will shift the focus on to Jack Straw, who was Foreign Secretary as the Bush administration launched its "war on terror". "The facts are that bad things were done by the Americans after 2002 and they didn't tell anyone else," Mr Miliband said. "Slowly the pieces of the jigsaw were put together and when they were put together the British government acted.

"Should we have been faster to put those pieces of the jigsaw together? Yes. But is it true that Britain's secret agencies act without ministerial or legal oversight? No. Is it true that serious allegations are swept under the carpet? No. They actually end up with police investigations, which is the strength of our system."

In a wide-ranging interview ahead of ballot papers being sent to Labour's 160,000 members this week, Mr Miliband seeks to present himself as the "unity candidate" capable of drawing together Labour's left and right. "The issue is not who can beat me; the issue is who can unite the party to beat David Cameron." He remains well ahead of Ed Balls, Diane Abbott and Andy Burnham. His closest challenger is his brother Ed, who suggested that under the last government foreign policy deviated from core Labour values.

But David Miliband, who became Foreign Secretary in 2007, maintains he always made the "right call" when balancing the need to "defend the security of the nation and uphold the values of the nation". He contrasts his brother's claim to have privately opposed the war in Iraq with the need for "consistency" in politics.

Mr Miliband says his insistence on "due diligence" in high office means his conscience is clear over allegations of a torture "cover-up", which persist after the last government lost a court battle to prevent the publication of American intelligence reports covering the treatment of Guantanamo Bay detainee Binyam Mohamed by the US in Pakistan in April 2002.

Mr Miliband claims credit for being the minister responsible for Mr Mohamed's release from Guatanamo and denies acting to suppress information to protect the reputations of Tony Blair and Mr Straw. He had released the documents to defendants' legal teams but opposed their being made public because "they weren't our documents".

The Liberal Democrats are preparing to use next month's party conference to embarrass Mr Miliband in a debate claiming Labour "backed" human rights abuses by the Bush administration, including "enforced disappearance, rendition and torture". Mr Cameron announced a judicial inquiry into Britain's role in torture and rendition – something Mr Miliband had resisted in his time in office.

Mr Miliband adds: "The hardest decision you can make in government is to turn down an exercise on the grounds that there might be a substantial risk to human rights abroad, in the knowledge that by turning it down you're forsaking the chance to do something to achieve greater security for people here. And that's a very difficult decision. You never ever have anything to do with torture. You never do. Under any circumstances. Because it is wrong."

Philippe Sands QC, a professor of international law at University College London, accused Mr Miliband of "burying his head in the sand". Speaking yesterday at the Edinburgh Book Festival, Professor Sands said he was "particularly interested in Mr Miliband's confirmation that the intelligence services acted with government oversight".

"He made unhappy arguments before the courts and the judges consistently rejected them. That raises issues of judgement. Mr Miliband could have done what Messrs Clegg and Cameron have done, and announce a proper inquiry to get to the truth. He failed to do so, and the fact that he still fails to see the error of that decision suggests that, as with Iraq, he's decided to bury his head in the sand."

Kate Allen, Amnesty International UK Director, said: "David Miliband is right to condemn the human rights abuses. But there's also compelling evidence that the UK was complicit in abuses overseas during this period. The forthcoming inquiry must be empowered to get to the truth."