WHEN AN independent Metro investigation found last year that D.C. Council member Jim Graham (D-Ward 1) had behaved unethically, his colleagues on the council essentially ducked. Now the District’s own ethics board has issued an even more damning report. Will the council — and, in particular, its tremulous chairman, Phil Mendelson (D) — duck again?

The investigation ordered by the Washington Metropolitan Area Transit Agency board of directors found that Mr. Graham had violated the agency’s code of conduct governing impartiality and conflict of interest. The report documented efforts by Mr. Graham in 2008, when he was serving on both the Metro board and the D.C. Council, to pressure a businessman to drop out of a Metro real estate deal in exchange for Mr. Graham’s support of the businessman’s separate bid for the lucrative D.C. Lottery contract. The report called into question Mr. Graham’s actions as a council member, but Mr. Mendelson took no action, deflecting questions from reporters. “I should speak to Graham personally before I answer any more questions,” the chairman said in refusing to even say if he had read the WMATA report.

Much to its credit, the D.C. Board of Ethics and Accountability took up the matter even without a referral from the council. Last week it produced a searing opinion that found “substantial evidence” that Mr. Graham had violated “at least” three sections of the D.C. Code of Conduct: “giving preferential treatment to any person,” “losing complete independence or impartiality” and “affecting adversely the confidence of the public in the integrity of government.”

On Friday Mr. Graham announced that he was rejecting our advice to resign. He has denied any wrongdoing and has faulted both the Metro investigation, conducted at a cost of $800,000, and the work of the ethics board, which his attorney called “disappointing and unfair.”

That puts the issue in the council’s lap. Council member Tommy Wells (D-Ward 6) has called for establishment of an ad hoc committee to consider evidence and make a recommendation for action. Council rules require such a committee before any penalties can be imposed, but it’s not clear what those penalties might be. The strongest action available to the council may be censure and loss of committee assignments. That was the treatment meted out to council member Marion Barry (D-Ward 8) when then-Chairman Vincent C. Gray, now mayor, realized the importance of sending a message about unworthy behavior (in Mr. Barry’s case, giving a contract and taking a cut to a girlfriend).

Once again, there’s been no comment from Mr. Mendelson, but he can’t stay mute forever. If the chairman and other council members register no objection to Mr. Graham’s behavior, they will be condoning it and thereby become complicit in the disgrace.