Washington ? The leaders of Congress’ ethics committees are not committing to any investigation of misconduct despite the growing revelations about the favors that lobbyist Jack Abramoff won for clients and the largesse he arranged for lawmakers.

The committees, for now, are remaining on the sidelines.

The House committee, stymied by partisan disagreements, launched no investigations in 2005 even after former House Majority Leader Tom DeLay, R-Texas, requested an inquiry into his foreign travel arranged by Abramoff.

The lack of commitment to investigate issues about lawmakers’ conduct with Abramoff, his lobbying team and his clients is raising anew the question of whether Congress adequately can discipline its own.

“There have always been questions about whether Congress can police itself,” said Kathleen Clark, a law professor at Washington University in St. Louis who specializes in ethics. “The situation in the House removes all doubt. The House is not policing itself.”

The Associated Press asked the four lawmakers who lead the ethics committees whether they would make a commitment to investigate ethical wrongdoing if, as expected, the information Abramoff supplies in a plea agreement exposes misconduct by a number of members of Congress. Each of the four – two Republicans and two Democrats – declined, through his spokesmen, to do so.

The House Committee on Standards of Official Conduct is headed by Rep. Doc Hastings, R-Wash.; the top Democrat is Rep. Alan Mollohan of West Virginia.

The Senate Select Committee on Ethics is led by Sen. George Voinovich, R-Ohio; the ranking Democrat is Sen. Tim Johnson of South Dakota.

While the committees have an equal number of Democrats and Republicans, forging a bipartisanship consensus in ethics investigations often has proved difficult.

Abramoff pleaded guilty this month to conspiracy, tax evasion and mail fraud in Washington and to additional charges in Miami. He has agreed to cooperate with prosecutors.

The committees traditionally defer to prosecutors and do not interfere with criminal investigations. But they can investigate violations of standards of conduct that are separate from criminal violations.