WASHINGTON — Former Enron chairman Kenneth Lay canceled an appearance Monday before a Senate committee investigating the bankrupt energy giant, and officials said lawmakers swiftly arranged to vote on a subpoena to compel his testimony.

These officials, who spoke on condition of anonymity, said the Senate Commerce Committee would convene Tuesday morning — 24 hours after Lay had been scheduled to testify on the largest bankruptcy in the nation's history.

The decision to seek a vote on a subpoena followed a closed-door session involving key members of the panel. A news conference was scheduled to announce the developments.

Lay canceled his planned appearance Monday on Capitol Hill after several senators and House members suggested on Sunday news shows that he and other company executives engaged in criminal acts.

Lay "cannot be expected to participate in a proceeding in which conclusions have been reached before Mr. Lay has been given an opportunity to be heard," his attorney, Earl Silbert, said in letters to the Senate and House panels that were to hear from him.

"These inflammatory statements show that . . . the tenor of the hearing will be prosecutorial," Silbert said.

Enron's former chief financial officer, Andrew Fastow, and ex-Enron executive Michael Kopper have indicated they will refuse to answer questions from Congress. Arthur Andersen auditor David Duncan, fired for his role in document shredding, invoked his Fifth Amendment right not to testify Jan. 24.

The Senate Commerce Committee canceled Monday's hearing, while the House Financial Services Committee said it would proceed, minus the former Enron chairman.

"I don't think he would have expected an appearance before Congress would be a walk in the park," Sen. Byron Dorgan, who would have presided over the canceled hearing, said Monday on network morning shows. But whether there is proof of securities fraud in the Enron collapse, Dorgan said: "I don't know that. ... There's a criminal investigation. Let's let the Justice Department determine that."

If Lay declines an invitation to appear later this month before the House Energy and Commerce Committee, "he'll be subpoenaed like everyone else," said panel spokesman Ken Johnson.

"We're going to meet with the committee members (Monday) and have a discussion about what we do next," Dorgan said.

Dorgan, D-N.D., dismissed Silbert's criticism, saying comments by members of Congress about possible criminality simply reflect assessments "by Enron's own accounting firm."

Andersen's chief executive testified at a House hearing in December that the accounting firm notified Enron's audit committee on Nov. 2 of "possible illegal acts within the company."

Lay's decision came the day after an Enron-authorized review of several of the company's estimated 3,000 off-the-books partnerships by University of Texas law school dean William Powers found that the energy trader's management concealed financial information from the public.

The report said the partnerships "were used by Enron management" to enter into transactions that "apparently were designed to accomplish favorable financial statement results, not to achieve bona fide economic objectives."

Andersen, the accounting firm, was accused in the report of facilitating a series of complicated transactions aimed at helping Enron conceal big losses and debts. Andersen announced that former Federal Reserve Chairman Paul A. Volcker would head an effort to overhaul the firm's practices.

Dorgan called Enron "almost a culture of corporate corruption" and said the Powers report is "a pretty devastating indictment of things that went on inside the corporation. The report would suggest that as CEO, Mr. Lay certainly was aware of much of this."

"Ken Lay obviously had to know that this was a giant pyramid scheme — a giant shell game," Sen. Peter Fitzgerald, R-Ill., said on NBC's "Today." Rep. Billy Tauzin, R-La., who chairs the House energy committee, asked whether "maybe somebody ought to go to the pokey for this."

After the Enron chairman announced he wouldn't testify, Fitzgerald said: "Mr. Lay is again taking a dive. ... Mr. Lay is the captain of the ship, and he needs to explain why his ship has sunk."

In his letters to Sen. Ernest Hollings, D-S.C., and Rep. Michael Oxley, R-Ohio, Silbert said "Mr. Lay firmly rejected any allegations that he engaged in wrongful or criminal conduct."

Hollings chairs the Senate Commerce Committee, Oxley the House Financial Services Committee.

In a letter to Silbert Monday, the Financial Services Committee's chief counsel called Lay's decision not to appear at the panel's Tuesday hearing "a most serious matter."

"We sought Mr. Lay's testimony in good faith and were assured it would be given," Terry Haines wrote. "I have called and e-mailed you, but have not heard from you. I await your call as soon as possible."

The Powers review of Enron also found that a key document was missing from a partnership deal. Lay says he was unaware of the transaction and former Enron chief executive officer Jeff Skilling says he was did not know the terms.

"We have not located any Enron Deal Approval Sheet, 'DASH,' an internal document summarizing the transaction and showing required approvals," the report said. It noted the same type of situation in another transaction as well, and it raised the possibility that no approval sheet was ever prepared.

Tauzin said Skilling, who left the company last summer after only six months as CEO, backed away from signing his name to off-the-books partnership deals.

"What does that say about his knowledge of whether these deals were honest or corrupt?" Tauzin said.

"We found out that one of the good guys ... went to Skilling and brought him all these deals to get his signature on it. He refused to sign it."