The head of the federal commission investigating the September 11 attacks threatened yesterday to subpoena the White House for access to documents vital to his work which he said had been kept from him by aides to President George W Bush.
Raising the prospect of a confrontation with the White House, Thomas Kean, the Republican former governor of New Jersey, told the New York Times that he would soon be forced to use his sweeping powers to subpoena intelligence reports sent to Mr Bush before the attacks.
The secret reports must be released to discover what the president knew before the attacks, said Mr Kean.
He would "not stand for" continued refusals to release papers and the commission would soon be forced to use "every tool at our command to get hold of every document", he said.
A White House spokesman said the executive branch believed it was co-operating fully with the commission, and hoped to meet all its demands for documents.
The White House agreed only reluctantly to the creation of the 10-member panel, which must complete its work by May next year, when its mandate expires.
Democratic members of the commission have accused the White House of deliberately stalling for political reasons to avert potentially explosive findings ahead of next November's presidential election.