By Jannat Jalil BBC correspondent in Washington

As President Bush announces he is setting up an inquiry into the intelligence used to justify the war in Iraq, a separate, on-going inquiry into the 11 September 2001 attacks threatens to overshadow his re-election campaign.

The White House has been accused of stonewalling the 9/11 inquiry

The independent commission was set up by Congress to establish exactly what happened that day, and what lessons can be learnt to prevent another such attack on US soil.

It was supposed to report back by 27 May, but it has asked for a two month extension to 26 July.

After initially opposing this, President Bush has now backed down. White House spokesman Scott McClellan says the Bush administration's main concern is to ensure the panel completes its work.

He said: "We worked very closely and co-operatively with the commission. We have been from the very beginning. And we were pleased to support their request for an extension.

the White House has basically stonewalled this investigation from day one Kyle Hence 9/11 Citizens Watch

"And I would emphasize to you that if they have information that can prevent something like 11 September from ever happening again, we want to have that information as soon as possible."

But political analysts say the Bush administration is also worried that any criticism of the government in the panel's report could be seized on by Democratic rivals during the presidential election campaign.

Calls for delay

At a public hearing last month, the commission strongly criticized immigration, aviation and intelligence officials for missing a series of clues - including fake passports and false visa statements - that could have stopped at least some of the 11 September hijackers.

There are fears the inquiry's findings will be over-politicised

Members of the commission have also complained repeatedly that their work has been delayed because of disputes with the Bush administration over access to documents and witnesses.

Even now, the commission is negotiating with the White House over access to notes that some of its members made on classified presidential briefing papers.

While they were allowed to make the notes, they were not allowed to take them away. But the commission's chairman, Thomas Kean, says it now has most of the material it has requested; it just needs more time to process it.

Mr Kean said: "We decided quite simply and frankly to put politics aside. We recognize there are opponents in Congress but as far as we as a Commission go we're telling the Congress and the president what we need, to do the best possible report for the American people."

But relatives of some of the victims of 11 September have called for the commission's report to be delayed still further, until January 2005, so that it doesn't get politicized.

Election issue

Kyle Hence of the group 9/11 Citizens Watch, which has been monitoring the panel's work, says the Bush administration tried to prevent it being set up in the first place and is still trying to hamper its work.

"We're in this situation - because the White House has basically stonewalled this investigation from day one," he said.

"And I don't think this commission has done a hard hitting job and I think that they're going to need more time to be held to account by the victims families and by those who are watching the process unfold."

The Republican senator John McCain, and the Democratic senator Joe Lieberman have also called for the inquiry to delay its report until after the presidential election.

Any delay would have to be approved by Congress, but there is opposition from both sides.

Republicans want the commission to stick to the original deadline of 27 May.

Democrats say delaying the report until after the election is depriving voters of information they are entitled to.