LONDON (AP) – Right after the Sept. 11 terror attacks, then-U.S. President George W. Bush talked about possible links between Saddam Hussein and Al Qaeda, a key adviser to former British Prime Minister Tony Blair said Monday.

David Manning, who served as a Blair’s top foreign policy aide before being appointed ambassador to Washington in 2003, told a British inquiry into the Iraq war that the issue came up in a phone call between the two leaders in the immediate aftermath of Sept. 11.

“He (Bush) said that he thought there might be evidence that there was some connection between Saddam Hussein and Osama bin Laden and Al Qaeda,” Manning told the inquiry, the most exhaustive study yet into the conflict and its genesis.

Manning said that Blair counseled caution. “The prime minister’s response to this was that the evidence would have to be very compelling indeed to justify taking any action against Iraq,” Manning said, adding that the British leader followed the conversation up with a letter stressing the need to focus on the situation in Afghanistan, where Al Qaeda was based.

The inquiry, which is in its second week, already has heard evidence that the U.S. was gearing up for war with Iraq within months of the 2001 terror attacks in the United States.

Although the inquiry will not apportion blame or hold anyone liable for the conflict, it does have the potential to embarrass officials in the U.S. and Britain who argued, wrongly, that the war was justified because Saddam was developing weapons of mass destruction and supporting Al Qaeda.

Jeremy Greenstock, the former British ambassador to the United Nations, told the inquiry on Friday that the U.S. was “hell bent” on war with Iraq from the very beginning and undermined efforts by Britain to win international authorization for the invasion. Manning’s predecessor as ambassador to the United States, Christopher Meyer, also testified that the U.S. was looking for connections between Iraq and Sept. 11 within hours of the attacks.

Manning said, “The Bush administration felt it has been caught napping by 9/11 and that this should not be allowed to happen again.” He said Blair accepted the possibility of military action in Iraq during a meeting with Bush at his ranch in Crawford, Texas, in April 2002. “I look back at Crawford as the moment that he (Blair) was saying: ‘Yes, there is a route through this that is an international, peaceful one, and it is through the U.N. But if it doesn’t work, we will be willing to undertake regime change.'”