WASHINGTON — Bringing together a diverse coalition of lawmakers, Rep. Charles Rangel of Harlem is taking another stab at his long-running push to ease trade and travel restrictions on Cuba.

Mr. Rangel, the Democratic chairman of the House Ways and Means Committee, is introducing a bill to end the travel ban and make it easier to export agricultural and medicinal products to the communist nation, which the State Department has designated as a sponsor of terrorism.

The bill is being introduced jointly in the House and Senate, and it has support on both sides of the aisle. But the lawmakers, including Mr. Rangel, acknowledged that they had seen no significant shift in the political landscape that would alter the opposition in many quarters to lifting the embargo. They are hoping that Democratic control of Congress and President Bush’s low standing in the polls will give the bill a chance.

“We hope this bipartisan group will be much more effective than we’ve been in the past,” Mr. Rangel said as he stood with Senator Baucus, a Democrat of Montana, Senator Crapo, a Republican of Idaho, and Rep. Jo Ann Emerson, a Republican of Missouri, at a Capitol press conference announcing the legislation. Citing the travel prohibition, he said it was an “insult” to all Americans for the government to tell them “where they can and can’t go.”

While Mr. Rangel has long fought for normalizing relations with Cuba, he has formed this coalition in the hopes of attracting broader support from representatives with farming constituencies.

“I just think our backwards policy toward Cuba hurts U.S. producers much more than it hurts Fidel Castro,” Ms. Emerson said.

Messrs. Rangel and Baucus, the head of the Senate Finance Committee, are trying to take advantage of their new chairmanships. By framing the bill so that it will land in the Ways and Means Committee in the House and the Finance Committee in the Senate, they can make it much more likely to come to a full vote on the floor.

The bill drew a swift response from a leading supporter of the embargo, Rep. Ileana Ros-Lehtinen, a Republican of south Florida. “Sending money to the Castro brothers will not do a thing to free the Cuban people from the oppressive chains that have tied them down for almost half a century,” Ms. Ros-Lehtinen, a Cuban American and the former chairwoman of the House Foreign Affairs Committee, said in a statement.

Opponents of the legislation also criticized its timing, pointing to Mr. Castro’s age and reported illness and chances for reform in the country after he dies. “It’s not the time to be experimenting,” a director of the U.S.-Cuba Democracy Political Action Committee, Mauricio Claver-Carone, said.

Mr. Claver-Carone said he wasn’t worried, however, that the embargo was in any danger from Mr. Rangel’s latest attempt to get it lifted. “At the end of the day, there’s no new dynamic,” he said. He cited the passage in the House yesterday of an amendment directing $45 million in American aid to Cuban dissidents, families of political prisoners, and other groups promoting democracy on the island.

Mr. Claver-Carone also took note of Mr. Rangel’s collaboration with lawmakers from the farm belt. “It’s interesting to see Mr. Rangel promoting agriculture trade, because he has so much agriculture in Harlem,” he quipped.

The bill would remove verification and prepayment requirements on agricultural exports to Cuba and allow direct payment by Cuban customers to American banks, among other provisions.