A government watchdog group Tuesday asked Congress to investigate whether lawmakers broke ethics rules by taking action that benefited lobbyist Jack Abramoff's tribal clients while accepting political donations from the lobbyist or the tribes.

Democracy 21 urged the House and Senate ethics committees to investigate following an Associated Press story last week that found several members of Congress intervened with letters to Interior Secretary Gale Norton within days of receiving large contributions from tribes represented by the lobbyist or using Abramoff's restaurant for fundraising.

They included House Speaker Dennis Hastert, R-Ill., and Senate Minority Leader Harry Reid, D-Nev.

The lawmakers urged Norton to reject the Jena tribe of Choctaw Indians' bid for a new casino in Louisiana. Some of Abramoff's tribal clients wanted to stop the project because it would compete with their casinos.

The lawmakers say their intervention had nothing to do with Abramoff and that they wrote letters because they opposed the expansion of tribal gaming.

Abramoff's activities are under investigation by the Justice Department.