Legislation to curb excesses of both lobbyists and lawmakers reached the Senate floor Monday as leaders from both parties warned that the integrity of Congress is at stake.

The legislation, which would require lobbyists to be more open about the meals they buy and the trips they arrange for members of Congress, is a response to the Jack Abramoff lobbying scandal that hit Washington with details of millions of dollars from Abramoff's clients going to win friends and buy influence on Capitol Hill.

It also comes just three days after former Rep. Randy "Duke" Cunningham, R-Calif., was sentenced to more than eight years in federal prison for accepting $2.4 million in bribes.

"It is time for us to re-examine the rules so that bad apples are exposed before they spoil the whole lot," Senate Majority Leader Bill Frist, R-Tenn., said in opening debate.

The Senate bill, which combines measures produced by two Senate committees last week, has already come under fire from advocacy groups and some lawmakers who say the proposed changes, the first to lobbying laws in 11 years, are mainly cosmetic.

The measure would require senators to reveal more information on their privately funded trips, but would not ban such trips as sought by some. The Homeland Security and Governmental Affairs Committee last week also rejected a provision to set up an independent ethics investigator to oversee lobbying and ethics questions.

"Overall, this measure is insufficient because it focuses on disclosing corruption, rather than deterring it," Public Citizen's Joan Claybrook said of that committee's bill.

But Senate Minority Leader Harry Reid, D-Nev., while blaming the recent scandals on "a Republican culture that has distorted government priorities," defended the Senate bill. "Maybe there are some outside groups who think we haven't done enough. We've done a lot." he said.

The section of the bill prepared by the Rules Committee deals with a major source of criticism of Congress: the special projects or earmarks that lawmakers insert in larger bills, often with little or no debate.

Under the measure, a senator could raise a point of order, stripping out any earmark inserted when the House and Senate negotiate the final version of a bill. It would take a 60-vote majority to waive that point of order.

The Rules Committee portion also would require lawmakers to post on their Web sites within 15 days any meals or drinks they receive from lobbyists and within 30 days details of privately funded trips. Gifts and travel directly paid for by lobbyists would continue to be banned.

Relatives of a senator who are registered lobbyists could not have official contact with the senator's staff, and senators could not pressure lobbying firms to hire people based on their political affiliation.

The Homeland Security panel's bill would require that retiring members of Congress wait two years before taking jobs lobbying Congress, and it would oblige lobbyists to reveal information about grass-roots lobbying, helping clients to encourage the general public — through mass mailings or advertising — to contact federal officials.

Lobbyists also would have to file reports quarterly, rather than the current rule of twice a year, on their contacts with lawmakers and their fundraising and political contribution activities.

Frist said he hoped to finish work on the bill by the end of the week. The House is also working on the lobbying issue, but GOP leaders there have yet to develop a specific plan.