Former US president George Bush said information obtained from terrorist suspects through “waterboarding” prevented attacks and saved British lives.
In his memoirs, serialised in the Times, he said the use of the controversial interrogation technique - which simulates drowning - had helped to break up plots to attack American facilities abroad, Heathrow Airport and Canary Wharf.
In an interview with the newspaper, the 43rd US president confirmed he authorised the use of waterboarding to extract information from Khalid Sheikh Mohammed, the al-Qaeda mastermind behind the 9/11 attack, telling the paper: “Damn right!”
Mr Bush said: “Three people were waterboarded and I believe that decision saved lives.”
In the book, Decision Points, he writes: "Their interrogations helped break up plots to attack American diplomatic facilities abroad, Heathrow airport and Canary Wharf in London, and multiple targets in the United States."
The British government has long rejected the use of waterboarding, which it regards as torture. In a speech last month, the chief of MI6 Sir John Sawers insisted that his service had “nothing whatsoever” to do with torture which he described as “illegal and abhorrent”.
Downing Street confirmed this afternoon that the British government still considered waterboarding to constitute torture. “It comes under that definition in our view,” a No 10 spokeswoman said.
In the interview, Mr Bush described his close relationship with Tony Blair, but was dismissive of public opinion in Britain about the war in Iraq.
“It doesn’t matter how people perceive me in England. It just doesn’t matter any more. And frankly, at times, it didn’t matter then,” he said.
Mr Bush recalled how when Mr Blair faced a possible vote of no confidence in the House of Commons on the eve of war, he offered him the chance to opt out of sending British troops into Iraq.
He said that “rather than lose the government, I would much rather have Tony and his wisdom and his strategic thinking as the prime minister of a strong and important ally”.
However, Mr Blair told him: “I’m in. If it costs the government, fine.”
The former governor of Texas also describes how he was appalled to discover that the intelligence about Iraq’s supposed weapons of mass destruction had proved to be wrong.
“The reality was that I had sent American troops into combat based in large part on intelligence that proved false,” he writes. “No-one was more shocked or angry than I was when we didn’t find the weapons. I had a sickening feeling every time I thought about it. I still do.”
Nevertheless he insists that he was right to take military action to remove Saddam Hussein. “There were things we got wrong in Iraq, but that cause is eternally right,” he writes.
He adds: “What would life be like if Saddam Hussein were (still) in power? It’s likely you would be seeing a nuclear arms race.”
According to the Guardian, which has obtained a copy of the book, Mr Bush discloses that he instructed a plan to be drawn up for a military strike on Iran's nuclear facilities.
“I directed the Pentagon to study what would be necessary for a strike,” he writes. “This would be to stop the bomb clock, at least temporarily.”
He says that he also considered mounting an air strike or a covert raid on a secret Syrian nuclear facility, but the Pentagon and the CIA concluded it was “too risky”.
Mr Bush uses his book to describe his battle to give up alcohol, saying it was “one of the toughest decisions I have ever made”.
He adds: “Being the sober guy helped me realise how mindless I must have sounded when I drank.”
PA