For years, Rep. Joel Hefley (R-Colo.) toed the Republican Party line, crusading against President Bill Clinton's health care system and voting for lower taxes. But this year Hefley, who chairs the House ethics committee, became a rebel, criticizing his own leadership for watering down House ethics standards and awarding committee chairmanships on the basis of fundraising and personal ties.

The fact that Hefley, after two years as chairman of the ethics panel, is publicly questioning House leaders' conduct could have profound implications for how the panel enforces ethics standards for members. For years leaders put loyalists on the panel, relying on them to either protect their party's interests or quietly dispose of cases where there was blatant wrongdoing.

But now Hefley -- an occasional rodeo performer and sculptor -- is becoming an unlikely force for change, insisting that his colleagues live up to how they promise to behave. Struggling against a tide of complacency that permeates Capitol Hill, Hefley said he has no choice but to challenge some of the most influential politicians in town.

"When you start disagreeing with the leadership, they have the power to punish you," Hefley said in a recent interview. "We'll just have to wait and see. I'm just telling it like it is."

A few weeks ago, Hefley publicly complained when GOP leaders rewrote House ethics standards without consulting him. Hefley said the provisions -- which allowed lobbyists to cater meals for House offices and fly out members for charity events -- looked "bad," adding later that members needed to avoid the appearance of "trying to weasel around ways to live high at someone else's expense."

Hefley also complained when he and other senior members were passed over for the chairmanship of the House Resources Committee in favor of Rep. Richard W. Pombo (R-Calif.). Hefley said the move was made "to solidify [House Majority Leader Tom] DeLay's power, because this guy is close to DeLay. I think that's wrong."

The panel Hefley chairs is equivalent to congressional Siberia, a place where members grudgingly put in long hours, deciding in secret whether to discipline their colleagues for accepting questionable gifts or giving lobbyists improper access. After a series of rancorous partisan fights that culminated in the ethics probe of then-House Speaker Newt Gingrich (R-Ga.), the two sides called a truce. For the past few years, Republicans and Democrats have worked quietly behind the scenes together to, in most cases, rebuke colleagues without calling for their ouster.

This cooperation has prompted several watchdog groups to attack the ethics committee as toothless. But a few have suddenly begun to see Hefley as a tentative reformer.

"It was very encouraging that the chairman of the ethics committee spoke out against backtracking on existing ethics rules," said Fred Wertheimer, president of Democracy 21. "One hopes that Chairman Hefley's courage in speaking out will lead to other members of Congress's willingness to challenge Majority Leader Tom DeLay when he's doing something that's wrong for the institution and the country."

Hefley's blunt comments have surprised some analysts who have watched him for years. At one point, Hefley was labeled by Roll Call, a newspaper that reports on Capitol Hill, one of the 10 most obscure members of Congress.

"We're just not accustomed to Joel playing a role in a national story," said Robert D. Loevy, a political science professor at Colorado College.

With one of the most Republican seats in the nation, the 16-year House veteran faces few consequences back home for his outspokenness.

It remains unclear whether the leadership will listen to Hefley and revise what is now known as "the pizza rule." In a brief interview recently, House Speaker J. Dennis Hastert (R-Ill.) would only say, "Every member has the right to criticize and be unhappy."

It is a dramatic switch for Hefley, who has devoted most of his time to defense and environmental issues. He counts among his legislative achievements a measure privatizing the construction of military housing and a bill requiring studios to pay for filming on national parks. Although not beloved by environmentalists, he is considered slightly more moderate than Pombo, who got the House Resources Committee chairmanship.

By all accounts, Hefley is popular with his colleagues on the ethics committee, even those who disagree with him politically.

"He's very aboveboard, very honest," said Rep. Zoe Lofgren (D-Calif.), who worked with Hefley during the ethics investigation of then-Rep. Bud Shuster (R-Pa.). "I grew to respect his integrity."

At the same time, some ethics advocates accuse him of coddling his colleagues rather than disciplining them. Gary Ruskin, of the Congressional Accountability Project, said the panel has failed to investigate lawmakers such as Rep. Paul E. Kanjorski (D-Pa.), who came under fire last year for steering federal contracts to a relative. The ethics committee does not reveal what cases it is investigating until it launches a formal probe.

"He has helped out the good old boy network evade investigations of corruption, abuse of power, influence peddling and the like," Ruskin said, adding that the fact that the House leadership ignored Hefley in drafting gift rules this month is "a sign they think he's a joke."

But Hefley said such criticism ignores what he envisions as the committee's role, saying he prefers to counsel lawmakers before they trespass rather than punishing them after the fact.

"My vision of it is this should be completely nonpartisan," he said, adding that when it comes to members, "I try to keep them out of trouble." Even in the midst of the recent uproar, Hefley can still joke about his job with former representative James V. Hansen (R-Utah), who persuaded him to join the committee in the first place.

"He's been trying to throw me down an elevator shaft ever since," Hansen said.

Rep. Joel Hefley (R-Colo.) has been chairman of the House ethics committee for two years.