Mayor Vincent C. Gray offered his first public apology Wednesday for his troubled 2010 campaign, seeking to address the main obstacle to a second term just days before his reelection kickoff rally.

“I didn’t do anything,” Gray (D) told WUSA (Channel 9). “At the same time, I want to apologize to people about the campaign. I can’t apologize for what other people did. But it was the Vincent Gray campaign, I understand that.”

The apology was aired at the top of WUSA’s 5 p.m. newscast Wednesday, and further excerpts from the lengthy interview were set to air on broadcasts later in the evening.

Gray granted the interview, his first extended Q&A since announcing his reelection bid, to longtime reporter and anchor Bruce Johnson ahead of a campaign kickoff rally scheduled for Saturday at a community center in Southeast Washington.

Gray declined to repeat the apology Wednesday night when asked about the interview after a community meeting in the Congress Heights neighborhood of Southeast Washington, where he laid out highlights of his administration and answered questions for 90 minutes.

Gray disputed the suggestion that it was his first public apology but did not identify other examples.

“I chose the opportunity to do it, and I have done it,” he said of the Channel 9 interview. “I invite you all to listen to it, and what I said stands for itself.”

The mayor’s television remarks Wednesday repeated several earlier comments he has made about the campaign missteps, including claims that he was too busy doing his job as D.C. Council chairman to keep a close eye on campaign doings.

But Wednesday was the first time Gray tendered a public apology for the wrongdoing: “The things that happened in my campaign, you know, were painful, they were embarrassing to me,” he said. “They were things that I wish hadn’t happened, and I’m sorry that those things happened.”

An ongoing federal investigation has resulted in guilty pleas to federal charges from several campaign associates, including a close confidant who had played key roles in Gray’s earlier campaigns. Court documents have laid out two secret schemes that involve violations of elections law — to secretly pay a fellow mayoral candidate to verbally attack the incumbent, and a “shadow campaign” allegedly financed by a city contractor that secretly pumped at least $650,000 into Gray’s election effort.

Gray has denied wrongdoing in general terms. After his sudden decision in December to seek reelection, Gray was defiant in addressing questions about what had happened in 2010.

“I’ve said what I’ve said, I’ve said it repeatedly, and, you know what? There’s no end to that,” he said Dec. 3, adding that “2010 is now getting ready to be four years ago, okay? And I want to talk about what happens going forward in 2014.”

The portions of the Channel 9 interview aired thus far, despite the softer touch, do not include further explanations of his knowledge of the illegal schemes laid out by prosecutors. Nor do they lay out to what extent Gray has cooperated with federal investigators.

Gray campaign manager Chuck Thies said Wednesday that Gray “is emphasizing . . . his apology is deep and heartfelt, and he needs to turn the page.”

Thies said he is confident the public is not overly concerned about the unresolved questions over Gray’s knowledge of or participation in any wrongdoing: “Certainly there are some journalists who care about the past, and if the mayor has to emphasize that he’s deeply sorry about 2010, then it’s necessary that he do that.”

Gray was careful not to mention his reelection bid during his remarks at the community event late Wednesday — a meeting of an elected advisory neighborhood commission. But political aides were in the room with fliers advertising Saturday’s kickoff, and several cabinet deputies were in attendance.

Near the end of Gray’s appearance, commission chairman Mary Cuthbert urged the audience to attend the rally and even suggested they bring money — an apparent breach of the legal firewall between government and partisan politicking.

Gray laughed nervously and then cracked — seemingly referring to his prior campaign troubles, which included allegations of illicit cash donations and expenditures — “don’t bring cash.”

It is unlikely the apology will tamp down his opponents’ efforts to play up the unfinished federal investigation and the cloud it has placed over Gray’s mayoralty.

“I’m glad he acknowledged the fact that his campaign further embarrassed our city,” said D.C. Council member Tommy Wells (D-Ward 6), who is challenging Gray in the Democratic primary.

But Wells said the apology should not quell voter doubts about Gray’s integrity, noting that Sulaimon Brown, the fringe mayoral candidate said to have been paid off by the campaign, initially got a job in Gray’s administration.

“I don’t see how the mayor is not disqualified after running an illegal campaign,” Wells said.