Colin Powell, former US secretary of state, advised President George W. Bush and Donald Rumsfeld, defence secretary, before the onset of war that the administration was not deploying enough troops to Iraq.

Mr Powell, joining a chorus of critics who have singled out Mr Rumsfeld’s handling of the war and the question of whether the US invaded Iraq with a sufficient number of troops on the ground, said in an interview on the UK’s ITV that the White House did not follow his recommendation.