Members of an independent commission appointed to investigate the Sept. 11, 2001, terrorist attacks warned yesterday that the panel will go broke by August without $11 million in new funding, which was not included in the Bush administration's supplemental war budget as members had expected.

The commission's chairman, former New Jersey governor Thomas H. Kean (R), said yesterday that he submitted a request to the White House last week for the additional money, which would come on top of the $3 million allocated by Congress last fall to launch the investigation.

The White House's war-related proposal announced on Tuesday included no new money for the commission, prompting members and some lawmakers to begin lobbying for the funding.

Kean said he was disappointed that the money was not included in the White House budget, but added that he is confident that the administration and Congress would arrive at a solution. The panel's proposed $14 million budget includes funding for about 50 staff members and for specially secured office space in downtown Washington.

"The White House has told me they support us being adequately funded, and I am confident that will be the case," said Kean, president of Drew University in New Jersey.

White House spokesman Scott McClellan said the administration is exploring ways to pay for the commission "without additional legislation."

The budget wrangling is the latest difficulty to confront the 10-member bipartisan commission, which was established by Congress at the urging of the families of victims of the terrorist attacks. The panel has been hampered by delays in the selection of its members, in obtaining security clearances and in establishing guidelines for how the group will handle classified material. The panel's first public hearing, scheduled for Monday and Tuesday in New York, will include testimony from Sept. 11 survivors and relatives of victims.

Most members have yet to receive the security clearances needed before they can review classified material, sources said, and the commission is still in the midst of negotiations with the FBI, the CIA and other agencies over guidelines on how to proceed. The panel also has not yet received a copy of the classified version of the report issued by a joint House-Senate inquiry into intelligence failures preceding the Sept. 11 attacks.

The panel has had difficulties from the start, when two top appointees, former secretary of state Henry A. Kissinger and former Senate majority leader George J. Mitchell (D-Maine), decided not to serve because of conflict-of-interest concerns.

Some commission Democrats and relatives of Sept. 11 victims have since complained that the panel's progress has been slowed in part by the apparent ambivalence of the White House, which had initially opposed the creation of an independent commission.

"The White House never really wanted this commission, and my fear is that they are looking for a way to kill it without looking like they've killed it," said Stephen Push, head of the group Families of September 11.

Said one commission member: "We've gotten off to a slow start, unfortunately, and part of that is because we've gotten mixed signals from the White House as to whether they support this."

McClellan said President Bush strongly backs the commission, which is required by law to finish its work by next spring. Kean said Bush's chief of staff, Andrew H. Card Jr., has issued a directive ordering all departments to cooperate with the investigators. "We are committed to seeing this succeed," McClellan said.

One sore spot for several commission members is NASA's investigation of the Feb. 1 Columbia shuttle disaster, which killed seven astronauts. Some estimates indicate the NASA probe could cost $50 million.

The joint House-Senate panel had a budget of nearly $3 million for an inquiry focused only on intelligence issues. The commission, by contrast, must investigate a wide variety of topics, from border policy to aviation security, Kean and others said.

"In the shuttle tragedy we lost seven people," said commission member Timothy J. Roemer, a former Democratic House member from Indiana. "We lost 3,000 people in the September 11th attacks, and we could lose more if these terrorists attack again. . . . Not going after the facts in this case could kill some people."