The year has not been kind to the speaker of the state Assembly, Sheldon Silver of Manhattan. In the past 12 months, he’s seen members of his Democratic majority investigated, indicted, convicted, and forced to resign. He himself was sued for failing to prevent a sexual assault by a former adviser. He has faced unusually intense criticism not just from Republicans, but also from fellow Democrats, such as the executive of Nassau County, Thomas Suozzi.

A study from New York University identified the state Legislature that Mr. Silver has helped to manage for the past decade as the most dysfunctional in the country. And, as if to prove the point, lawmakers missed a court-imposed deadline to overhaul funding for public schools and set a new record for the latest state budget in history.

As many bad days as he has had so far in 2004, however, Tuesday, September 14, will undoubtedly count among the worst. Tomorrow morning is when Mr. Silver is scheduled to sit down across a conference table from someone he views as a political enemy, David Grandeau of the state Lobbying Commission, and answer questions about his two-night stay in a Las Vegas hotel in January 2002.

Sometimes, it turns out, what happens in Vegas does not stay in Vegas. The commission is investigating whether the owner of the Paris Las Vegas hotel, Caesars Entertainment, made an illegal gift to Mr. Silver by charging him only $109 a night for a luxury suite with a list price of $1,500. Caesars is seeking approval to build a casino in New York, and companies with business before state government are forbidden from giving public officials anything worth more than $75.

The Lobbying Commission has no jurisdiction over Mr. Silver, and has not directly accused him of any wrongdoing. Still, the investigation has subjected the most powerful Democrat in state government to the embarrassing implication that he lived it up in Sin City courtesy of a company that was currying his favor.

When word of the Caesars probe first leaked to the New York Post in March, Mr. Silver indignantly insisted that he had done nothing wrong. In a rambling account for reporters, he said he and his wife decided on a whim to make their first visit to the gambling mecca after meeting their daughter’s future in-laws at San Francisco. He described shopping for travel bargains on the Internet and tracking down a hotel within walking distance of an Orthodox synagogue. He spoke of strolling on the famous Las Vegas strip, driving into the desert, visiting casinos, and catching a concert by the 1970s funk band Earth, Wind, & Fire. “It was just wonderful,” he said of the trip.

Mr. Silver showed a remarkable memory for events that had happened more than two years ago. He described booking a Chrysler 300 rental car for $16 a day onPriceline.com, and getting a good deal on a sweater at the Gap.

However, there were some blank spots in his account. He could not recall why he chose to stay at the Paris Las Vegas, how he wound up in a 1,140-square-foot suite usually reserved for high rollers and VIPs, or how he and his wife came to dine with a top lobbyist for Caesars and her husband. He did say that the get-together included “zero” discussion of public business.

“I am troubled to learn from the press that this is a great big story,” he said in March. “I can only tell you that I have tried to conduct myself in an appropriate fashion.”

If Mr. Silver can shed more light on what happened at Las Vegas two and a half years ago, he will no doubt get the chance to do so tomorrow morning. And the public won’t have to wait to hear what he says: According to Mr. Grandeau, the speaker is to give his deposition at a public meeting of the commission, having passed up the option to do it privately.

For his part, Mr. Grandeau maintains that tomorrow’s session – apparently the first time the commission has questioned a public official under oath – would be unnecessary if Caesars were more forthcoming. “This is something we were forced to do because of the actions of Caesars,” he said.

An attorney and lobbyist for Caesars, James Featherstonhaugh, called that claim “patently ridiculous.” He said Mr. Grandeau has made unreasonable demands, including a record of every New York public official who has stayed at a Caesars-owned hotel over the past two and half years, including details about the rooms, dates, and charges – which would require searching company records for thousands of names.

Mr. Featherstonhaugh made the case that the discount provided to Mr. Silver was not unusual, especially during the downturn in tourism after September 11. On the days Mr. Silver stayed at the Paris Las Vegas, suites similar to his rented for as little as $69 a night and no more than $450, Mr. Featherstonhaugh said. The rate Mr. Silver paid, of $109, was not much below the average of $120, he said.

“The clear purpose of Mr. Grandeau’s insistence on the speaker’s appearance is just theater,” Mr. Featherstonhaugh said. “He’s not inclined to be reasonable or rational. His modus operandi is to just be aggressive.”

A political watchdog with the New York Public Interest Research Group, Blair Horner, said it looks to him as if Mr. Grandeau is merely doing his job. “I don’t necessarily view it as overzealous,” Mr. Horner said. “If the question is, ‘Should the lobbying commission be looking into whether a powerful special interest gave an illegal gift to a lawmaker?’ I think the answer is yes.”