Ban on Insider Trading by Congress Faces G.O.P. Revisions in House WASHINGTON - Lobbyists were in a tizzy on Tuesday over provisions of a Senate-passed ethics bill that tighten regulation of lobbying and require secretive "political intelligence" firms to register in the same way as lobbyists. House Republicans and their floor leader, Representative Eric Cantor of Virginia, said they would amend the bill, going to the House floor this week, to strengthen it. But Representative Louise M. Slaughter, Democrat of New York, said, "I think "strengthening" here is a euphemism for "weakening." " And Representative Tim Walz, Democrat of Minnesota, said the bill, to ban insider trading by members of Congress, was being rewritten behind closed doors by House Republican leaders. "How ironic," Mr. Walz said. Insiders now appear to be writing a bill meant to ban insider trading. The bill is intended to restore trust in Congress, but Mr. Walz said the revisions could "make the cynicism that's rampant in America even greater." The thrust of the bill, passed in the Senate last week by a vote of 96 to 3, is to prohibit members of Congress from trading stocks and other securities on the basis of confidential information they receive as lawmakers. An amendment offered by Senator Charles E. Grassley, Republican of Iowa, requires individuals or firms that collect intelligence from political insiders to register as lobbyists do. At present, Mr. Grassley said, when lawmakers and their aides meet with "political intelligence consultants," they have no way of knowing if the information they share will be sold to hedge funds, private equity firms or other investors who make a profit on it. Ms. Slaughter, who introduced insider trading legislation in 2006, said the regulation of political intelligence-gathering was "the most important part of the bill." Howard Marlowe, president of the American League of Lobbyists, a professional group, said, "The legislation moved so quickly that we did not have an opportunity to discuss it with Senator Grassley or his staff." Under the bill, Mr. Marlowe said, "the definition of political intelligence is very fuzzy." It includes information derived from contacts with Congress or federal agencies that is "intended for use in analyzing securities or commodities markets, or in informing investment decisions." J. Patrick Cave, managing partner of the Cypress Group, which does lobbying and policy research for investors, said: "People are freaking out about the Grassley amendment. For many, it's new, and it remains rife with loopholes, but it's a good start, clarifying the law and expanding disclosure requirements to include everyone. Mr. Cave and other experts on lobbying said the bill would require companies like Goldman Sachs and Morgan Stanley and law firms like Patton Boggs to register and disclose the clients for whom they did policy research analyzing developments in Washington. Michael W. Mayhew, who has analyzed the demand for such services as chairman of Integrity Research Associates in New York, said the global market for political intelligence services exceeded $400 million a year. He estimated that close to 300 companies systematically collected such information. Under the bill, Mr. Mayhew said, some of the political intelligence coming out of Washington would be classified as "material nonpublic information" and "people who invest on it could go to jail for insider trading." In a bulletin sent to clients this week, Covington & Burling, one of the largest law firms in Washington, said the bill could have an immense impact on "the business community." "Hedge funds, private equity funds and investment advisers - many of which are not currently registered under the Lobbying Disclosure Act - might now be required either to register or to alter their business practices to avoid the need for registration," the bulletin said. If, for example, a hedge fund calls a Congressional committee staffer to gather information about the status of a bill that relates to the fund's investment decisions, the fund may need to register. Robert K. Kelner, chairman of the political law practice group at Covington & Burling, said: "We have been flooded with calls about this legislation. I suspect there is a lot of lobbying to change it. Indeed, said Representative Slaughter, critics are "flooding Congress to try to weaken this bill." House Republicans said they would add a provision to prohibit members of Congress, their aides and executive branch officials from receiving special access to initial public stock offerings because of their positions. Republicans call this "the Pelosi provision" because, they say, it was inspired by an investment in 2008 by Representative Nancy Pelosi of California, who was then the speaker and is now the House Democratic leader. An aide to Ms. Pelosi said that neither she nor her husband, Paul F. Pelosi, had received "preferential treatment" when the company, Visa Inc., went public.