A split opened up between the UK and the United States over a claim that Iraq sought to buy uranium from the West African state of Niger. The US acknowledged for the first time that the claim might be wrong and that President Bush should not have referred to it in his State of the Union speech in January. But UK Prime Minister Tony Blair defended the assessment and told a committee of MPs on Tuesday that it was not a "fantasy" and that the intelligence services themselves stood by the allegation. The allegation was originally contained in the British Government dossier on Iraq's alleged weapons of mass destruction.