The Washington Post says people with direct knowledge of the call say Alberto Gonzales, President Bush's top lawyer, called commissioner Fred Fielding and may also have called commissioner James Thompson, before Richard Clarke was due to appear on March 24.
Clarke, the counterterrorism chief under President Clinton and Mr. Bush, alleges the Bush administration failed to take the threat of al Qaeda seriously before Sept. 11, instead focusing on Iraq.
, which cut to the heart of the president's national security performance, prompted a furious White House response.
National security adviser Condoleezza Rice appeared on CBS News 60 Minutes on Sunday to refute the charges, and the White Houseand said they would allow Rice to appear before the commission in public, under oath. She had previously appeared only in private.
Rice and other aides to the presidentand assailed his credibility.
Fielding and Thompson both asked questions on March 24 that concerned Clarke's credibility. Fielding referred to a previously classified briefing Clarke gave to Congress in 2002 in which he reportedly praised the Bush administration's terrorism strategy.
Thompson mentioned a White House briefing in 2002 that Clarke had given anonymously. Fox News first reported on Clarke's White House briefing just hours before.
Gonzales and Fielding did not talk to the Post and Thompson said, "I never talk about conversations with the White House," and that the questions he asks are his own.
Rep. Henry Waxman, D-Calif., said in a letter to Gonzales that any contact he made with commissioners might be improper because "the conduct of the White House is one of the key issues being investigated by the commission."
Waxman's complaint is the latest to voice concerns about certain conflicts of interest on the panel. Several commissioners and staff members have had to recuse themselves from discussing certain topics because they touched on past government or corporate experience.
Executive director Philip Zelikow, for example, served on Mr. Bush's foreign intelligence advisory board from 2001 to 2003 and co-authored a book, "Germany Unified and Europe Transformed," with Rice.
Commissioner Jamie Gorelick was counsel to the Pentagon and then a deputy attorney general during the Clinton administration.
Gonzales may have been in contact with the commissioners because he was involved in negotiations over whether Rice would testify in public.
In a reversal, the White House agreed Tuesday to allow Rice to testify publicly and under oath before the 10-member panel as early as next week. The administration previously had insisted she meet privately with the commission, citing constitutional concerns, but eventually bowed to public pressure.
The panel and relatives of Sept. 11 victims say they want Rice to clear up, under threat of perjury, conflicting statements made by herself and Clarke. Most of the contradictions concern the posture and policy of the Bush administration on terrorism before the 2001 attacks.
Rice has said the White House was focused on the al Qaeda threat. But the Post reports that in a speech Rice was due to give on Sept. 11, she indicated the country's most pressing security need was missile defense.
In the undelivered speech, Rice talked about "the threats and problems of today and the day after, not the world of yesterday," the Post reports, quoting officials who have seen the text. But she never mentioned Osama bin Laden, al Qaeda or Islamic terrorism. Instead, she focused on the threat of rogue nations launching ballistic missiles at the United States.
James R. Wilkinson, deputy national security adviser for communications, told the Post: "The president's commitment to fighting terrorism isn't measured by the number of speeches, but by the concrete actions taken to fight the threat."
On Thursday's CBS News Early Show, Sen. John McCain, R-Ariz., denied that the Bush administration neglected terrorism in favor of plotting against Iraq.
"I believe the facts speak for themselves. The facts are after 9/11, we knew where al Qaeda was and we knew it was in Afghanistan," McCain said. "We went to Afghanistan and we have now got a chance for a democracy there. That was the proper thing to do. We didn't go to Iraq first."
Mr. Bush and Vice President Dick Cheney, who had previously agreed only to meet the commission chairman and vice-chairman, this week agreed to meet with the full commission. But they will do so in private and together.