WASHINGTON — Utah's Sen. Orrin Hatch was one of just two senators to vote against a sweeping ethics reform package late Thursday because he was concerned that many of the provisions were either unconstitutional or overly restrictive.

On Friday, backers of the bill criticized Hatch for op- posing it. Democratic senators hailed the bill the most significant ethics and lobbying legislation in the history of the country.

The bill, which passed 96-2, would require senators to give up gifts and free travel from lobbyists, pay more for travel on corporate jets and more clearly identify pet projects they insert into bills, among a slew of other provisions.

The House already has adopted many of the same rules in a measure that applies only to its members. Speaker Nancy Pelosi of California said Friday that the House will begin drafting legislation similar to the Senate's measure.

Hatch, R-Utah, and Sen. Tom Coburn, R-Okla., cast the lone votes against the Senate bill.

Hatch defended his decision, saying he became increasingly uncomfortable with the package as the Senate voted for one amendment after another Thursday evening.

"I voted for most of the amendments, but the more I thought about it, the more I thought, 'Some of these I shouldn't have voted for,'" he told The Associated Press on Friday.

Among Hatch's concerns were that provisions designed to stop the revolving door of former lawmakers and their staffers returning to Washington as lobbyists could unfairly restrict constitutional rights.

"You can't treat people who work here for years and years as crooks because they leave here to go lobby," Hatch said.

Restrictions on lawmakers' travel might cost taxpayers more money, he said.

He also guessed that no one in the Senate knew exactly what was in the final bill because of the flurry of amendments.

"This bill is called the Transparency Act," he said. "I mean, come on. I don't think it's very transparent."

Backers of the legislation said the ethics bill was no different from other major bills Hatch has voted for.

"Is the Senate process as transparent as we would like? Probably not," said Meredith McGehee, policy director for the Campaign Legal Center. But she added: "To pick on this bill is really reaching. It didn't provide an excuse for the 96 other senators" who voted for it.

Hatch said he isn't worried about being called unethical. "I think only an idiot would do that. I do what I think is right up here. If I'm wrong I'll change."

Sen. Bob Bennett, R-Utah, also had concerns about the bill, although he voted for it. One was addressed in an amendment Bennett pushed that stripped a provision requiring reporting of "grass-roots" lobbying. The provision would have required more disclosure by special interest groups that use "hired guns" to organize mass mailings, phone-ins or e-mail campaigns.

Opponents, including religious groups, argued that the provision was a free-speech issue, and would discouragediscouraging people or groups from organizing petition drives.