Britain and America's preoccupation with Iraq has blocked international efforts to end genocide in the war-torn Darfur region of Sudan, according to a highly critical report published by a think-tank close to Tony Blair.

Britain and America's preoccupation with Iraq has blocked international efforts to end genocide in the war-torn Darfur region of Sudan, according to a highly critical report published by a think-tank close to Tony Blair.

The study, to be published today, said that the war in Iraq had prevented effective planning for military intervention which could have bolstered diplomatic efforts to prevent the bloodshed, which has driven more than a million people from their homes.

It warned that discussion on Iraq had prevented the United Nations Security Council discussing the Darfur crisis in May and diverted attention from clear warning signs that started emerging more than a year ago.

The study, which was published by the Foreign Policy Centre, a left-of-centre think-tank which counts Mr Blair as its patron, said that there was a fatal lack of political resolve to take strong action against the Khartoum government, a key American ally in the war on international terrorism.

Yesterday the report's author, Dr Greg Austin, a specialist who has led Government funded research into conflict prevention, said the lessons of the Rwandan genocide had not been learnt. He said British and American military action in Iraq had prevented the two countries considering putting "boots on the ground" in Sudan, and criticised the United Nations for omitting Darfur from the agenda of the Security Council in May "since the focus of discussion was on Iraq".

A string of options ranging from sanctions to developing contingency plans for military action had been available as clear signs of genocide emerged over the past year, the report maintained.

"During the Darfur genocide, these options were available to the international community as early as September 2003. By June 2004 no action had been taken in any way that might credibly have led the perpetrators to cease the genocide," it said.

The report fiercely criticised Britain and the United States for backing "quiet diplomacy", arguing that such an approach was "utterly inappropriate" for the situation in Darfur.

It added: "Major powers and the UN have been fearful of angering Khartoum before it concludes a peace agreement in its civil war in the south.

"Furthermore, the political leaders of some major powers may lack the political resolve to intervene in Darfur because of their commitments elsewhere in the world. Major powers do not want to jeopardise good relations with the Sudanese government in the 'war on terrorism'," the report said.

Dr Austin, who said he wrote his report in a personal capacity, insisted that the whole of the international community had failed to act in Darfur.

But he warned: "The commitment of the US and the UK in Iraq and the use of military force in Iraq pushed them away from considering any sort of military option...

"What the Iraq war should not have prevented them from doing was working on the possibility of international partners to find somebody willing to take on some role. There was nothing stopping them getting together a coalition of the willing to start to plan things."

Ministers have insisted Britain is at the forefront of aid efforts in Darfur but Dr Austin said politicians risked overlooking the perpetrators of genocide by characterising the conflict as a humanitarian crisis.

John Bercow, the shadow Secretary of State for International Development, called on ministers to back an international force to secure aid efforts in Darfur and to police a ceasefire. He said: "We are at 59 minutes after the 11th hour. Every day lives are being lost, women are being raped and lives are being destroyed. It is an unstable, dangerously failing state."

The US told UN Security Council members yesterday to be ready to vote this week on a resolution warning Sudan to protect Darfur civilians.