D.C. Del. Eleanor Holmes Norton and Mayor Vincent C. Gray have generally been close allies. (Sarah L. Voisin/THE WASHINGTON POST)

Del. Eleanor Holmes Norton (D) in a statement referred to the recent federal prosecutions of campaign operatives — including Tuesday’s revelations of a $653,800 “shadow campaign” working secretly on Gray’s behalf — as “deeply disturbing.”

“Mayor Gray has an obligation to clear this matter up quickly,” she said.

Norton referred to Gray as a “longstanding” friend “who I have always known to have high professional and ethical standards.”

“However,” she continued, “the criminal conduct by his campaign aides revealed in court is deeply disturbing and goes to the heart of the democratic process.”

Gray has decried the recent prosecutions in general terms but has not addressed the specific charges in the various cases.

Prosecutors have not alleged that Gray participated or had knowledge of the illegal schemes — which, besides the “shadow campaign,” included a straw donation ring and an arrangement to secretly pay a minor candidate to verbally attack Gray’s main opponent, incumbent Adrian Fenty..

Three D.C. Council members called for Gray’s resignation Wednesday, the first elected city leaders to do so. Gray repeated Thursday that he has no plans to resign.

Norton’s statement comes a day after her former chief of staff Donna Brazile, now a prominent political consultant and television commentator, expressed dismay at the latest charges on Twitter. “Mayor Gray has some explaining to do,” she tweeted, adding that the allegations represented a “nightmare for D.C.’s image.”

“Mayor Gray cannot hide behind his lawyers or public relations consultants,” she said. “He knows what happened. Now, tell it and let this city move on.”

Also of note: Norton in 2009 recommended the appointment of Ronald C. Machen Jr., the U.S. attorney who has led the investigation into the Gray campaign.

In the statement, Norton said she has seen “no evidence” the allegations have affected District matters on Capitol Hill. Gray has made the congressional approval of budgetary autonomy for the District one of his top priorities, but the proposal stalled in the Senate last month.

“We have been fully able to process our business through the House and Senate, including some difficult matters,” Norton said. “Cities and states across the country have faced similar investigations, and like the District, they have moved to address them.”