By Demetri Sevastopulo

US President George W. Bush attempted to boost support for the Iraq war yesterday by outlining details of alleged efforts by Osama bin Laden to plan attacks against the US from Iraq.

Delivering the commencement speech at the US Coast Guard Academy, Mr Bush disclosed previously classified intelligence asserting that in 2005 al-Qaeda's leader tasked Abu Musab al-Zarqawi, the former head of al-Qaeda in Iraq who was killed in a US air strike last year, with creating a terrorist cell in Iraq that would focus on plots to attack the US.

Democrats and Bush adm-in-istration critics pounced on the move, which the White House hoped would help convince Americans that success in Iraq is crucial to protecting the US from terrorism threats.

Mr Bush is facing pressure from Republicans to demonstrate success in Iraq by September, when General David Petraeus, the top US commander in Iraq, will provide a report on the "surge".

"Intelligence analysts concluded long ago that Iraq has indeed become a training ground and recruiting poster for a new generation of terrorists," said Harry Reid, the

Democratic Senate majority leader. "That is exactly why it is so important to change course from the president's failed Iraq strategy to a new strategy that more effectively fights terrorists."

Richard Clarke, the former senior Bush administration White House counter-terrorism chief, accused Mr Bush of sending conflicting messages on the role of terrorists operating from Iraq.

"One day Bush tells us we are fighting in Iraq so that terrorists won't come here, then he releases intelligence that says terrorists trained in Iraq are coming here. Which is it?" said Mr Clarke.

Earlier this year the office of the director for national intelligence released an estimate on Iraq that concluded that sectarian violence was the biggest problem. But in recent months administration officials, and Gen Petraeus, have focused on the threat from al-Qaeda.

Frances Frago Townsend, the White House homeland security and counter-terrorism adviser, dismissed suggestions that the administration was playing politics by releasing the classified information. "Frankly, if political advantage was the name of the game, we would have gotten it out a lot sooner," said Ms Townsend.

A recent USA Today/Gallup poll found that 50 per cent of Americans disapprove of the job Mr Bush is doing handling terrorism. A separate Associated Press-Ipsos poll found 64 per cent of respondents disapproved of his performance on Iraq.