Bob Ainsworth, the defence secretary, has blamed Barack Obama and the United States for the decline in British public support for the war in Afghanistan.

The Defence Secretary's blunt remarks about the US threaten to strain further a transatlantic relationship Photo: REUTERS

Mr Ainsworth took the unprecedented step of publicly criticising the US President and his delays in sending more troops to bolster the mission against the Taliban.

A “period of hiatus” in Washington - and a lack of clear direction - had made it harder for ministers to persuade the British public to go on backing the Afghan mission in the face of a rising death toll, he said.

Senior British Government sources have become increasingly frustrated with Mr Obama’s “dithering” on Afghanistan, the Daily Telegraph disclosed earlier this month, with several former British defence chiefs echoing the concerns.

But Mr Ainsworth is the first Government minister to express in public what amounts to personal criticism of the US president’s leadership over the conflict which has so far cost 235 British lives.

Polls show most voters now want an early withdrawal, following the death of 98 British service personnel this year alone.

Ministers say the mission is vital to stop international terrorists using Afghanistan as a base, but Gordon Brown has promised an “exit strategy” that could start next year.

The Defence Secretary’s blunt remarks about the US threaten to strain further a transatlantic relationship already under pressure over the British release of the Lockerbie bomber and Mr Obama’s decision to snub Mr Brown at the United Nations in September.

Mr Ainsworth spoke out as the inquiry into the 2003 war in Iraq started in London, hearing evidence from British diplomats that the UK government concluded in 2001 that toppling Saddam Hussein by military action would be illegal.

Mr Obama has been considering advice from General Stanley McChrystal, the US commander in Afghanistan, to send more than 40,000 extra troops to the country.

Next week, after more than three months of deliberation, the president is expected to announce that he will send around 34,000 more troops.

Mr Ainsworth, speaking to MPs at the defence committe in the House of Commons, welcomed that troop 'surge' decision, but lamented the time taken to reach it.

He said that the rising British death toll, the corruption of the Afghan government and the delay in Washington all hamper efforts to retain public backing for the deployment.

“We have suffered a lot of losses," he said. "We have had a period of hiatus while McChrystal's plan and his requested uplift has been looked at in the detail to which it has been looked at over a period of some months, and we have had the Afghan elections, which have been far from perfect let us say.

“All of those things have mitigated against our ability to show progress... put that on the other side of the scales when we are suffering the kind of losses that we are."

Britain has 9,000 troops in Afghanistan and has announced it will send another 500, a decision some US officials saw as a move to put pressure on Mr Obama.

Mr Ainsworth said he is confident that once Mr Obama confirms his new strategy, allies will follow and British public opinion will shift back in favour of the mission.

“I hope and believe that we are about to get an announcement from the USA on troop numbers and I think that that will be followed by contributions from many other Nato allies and so we will be able to show that we are going forward in this campaign to an extent that we have not been able to in recent months with those issues still hanging,” he said.

Mr Ainsworth was appointed defence secretary earlier this year, his first Cabinet post.

A former factory worker and union official, he has faced questions about whether he has the stature or political clout to oversee the Armed Forces at a time of war.

In August, he told The Daily Telegraph he was less intellectually accomplished than the commanders who answer to him and suggested that his critics are motivated by class prejudice.

A report earlier this week suggested that Mr Brown is considering removing Mr Ainsworth and replacing him with Jack Straw, the Justice Secretary.

Attempting to play down Mr Ainsworth's remarks, No 10 and the Ministry of Defence last night made a statement backing Mr Obama's deliberations.

It stated: "It is right that Nato partners have taken the time to review next steps in the campaign. These are hugely important issues that rightly need careful and detailed consideration."

In an article in this newspaper today Nick Clegg, the Liberal Democrat leader, claims that the reason public opinion is switching against the war in Afghanistan is because of the lies told in the run up to the Iraq war.

Mr Clegg also calls for a new approach to Afghanistan from the US. He writes: “We now need a complete change of strategy, which we still hope President Obama will announce next week.”

White House sources said yesterday that Mr Obama is preparing to address Americans in a live prime-time broadcast next Tuesday followed by testimony before Congress by senior figures such as General Stanley McChrystal, commander of Nato forces in Afghanistan, and Karl Eikenberry, US ambassador to Kabul.

Mr Obama is believed to have decided to send about 34,000 more American troops in addition to the 68,000 currently in Afghanistan. Gen McChrystal requested about 40,000 more soldiers.

The US president convened a group of senior officials, including Vice President Joe Biden, Secretary of State Hillary Clinton and Mr Gates in the White House Situation Room on Monday night for a ninth and final “war council” meeting.