D.C. Council Chairman Kwame R. Brown started his day Tuesday by calling some of his colleagues into his office. One by one, he told them to expect big changes on the 13-member body.

He was giving up the chairmanship of the council’s Economic Development Committee, a portfolio he had coveted for years and a centerpiece of his 2010 campaign to lead the D.C. Council.

Brown’s conversations and his decision to quit the panel fueled rampant speculation that the 41-year-old is preparing to step aside as a federal investigation of his finances and 2008 campaign intensifies. If true, he would become the second council member under scrutiny by the U.S. Attorney’s Office to resign this year.

But after a day when reporters stalked him and some of his colleagues drew up plans for a possible post-Brown council, he met with reporters in his office for an afternoon announcement.

“I have no plans to resign,” Brown said. “That is all I am going to say. . . . I have no plans at this time to resign.”

That Brown (D) had to address the hearsay about his political demise underscores the drama in the John A. Wilson Building nearly two weeks after two campaign aides to Mayor Vincent C. Gray (D) pleaded guilty to federal charges in a separate investigation of the mayor’s 2010 campaign.

For more than a year, the U.S. Attorney’s Office has been looking into whether Brown violated any laws when his 2008 reelection campaign diverted $239,000 to a now-defunct consulting firm owned by his brother, Che Brown. Around that time, Brown was badly in debt, resulting in four lawsuits from credit card companies seeking payment of more than $50,000 in unpaid bills. He has settled the suits.

Two years ago, The Washington Post reported that Brown had estimated the value of his home at $850,000 on a 2006 credit card application, even though the assessment on his property was $357,930 at the time.

A grand jury has been empaneled as part of the federal investigation, and people familiar with the probe told The Post that the inquiry is drawing to a close.

Speaking to reporters on Tuesday, Brown stressed that he was not going to comment on the investigation but reiterated that he’s confident he violated no laws related to the 2008 campaign.

Still, Brown is showing signs of strain as he executes his responsibilities with the weight of the investigation.

About midday Tuesday, as Brown rushed toward the council chamber, WTOP reporter Mark Segraves attempted to question the chairman about the inquiry. According to WTOP, Brown “shoved his forearm into Segraves’ chest and pushed him up against the wall.”

A few hours later, Brown apologized to Segraves.

“Mark ran up on me in a room that council members and staff are only allowed into, and I didn’t know who that was,” Brown told reporters. “I told Mark I apologize if he felt shoved. That was not my intent at all.”

Brown kept a cooler head as he presided over a round of votes on issues ranging from an overhaul of taxi regulations to a bill to curb youth bullying.

“I think this budget shows this council is well prepared to be fiscally responsible while protecting the interests of the people who sent us here,” Brown said after the council approved the budget for fiscal year 2013.

Behind the scenes, however, Brown was working to round up member support for his plan to reshuffle committees.

He created a panel so that new council member Kenyan R. McDuffie (D-Ward 5) could chair the Committee on Jobs and Workforce Development. McDuffie was elected in a May 15 special election after the resignation of Harry Thomas Jr., who has been sentenced to prison for stealing $350,000 from the city.

That meant Brown took some authority from council member Michael A. Brown (I-At Large), who headed the Committee on Housing and Workforce Development.

But Kwame Brown gave up his oversight over economic development and merged it with what was left of Michael Brown’s committee, establishing a new Economic Development and Housing Committee.

Although Kwame Brown said he planned to relinquish his responsibility for economic development, the decision was seen by some as bringing more uncertainty to District government.

Council member Phil Mendelson (D-At Large) said several of his colleagues have approached him with concerns about how the body would address a possible Kwame Brown resignation.

“A lot of members have been talking about the rumors and really trying to understand what might be happening,” Mendelson said. “People are talking. . . . Members are concerned both about the rumors and recent events about the mayor, upset that the government is not looking good right now.”

Under the Home Rule Charter, council members would select an interim chairman from among the four at-large members if Brown stepped aside. Mendelson is viewed as a leading contender for such an interim appointment.

When Brown met with reporters Tuesday afternoon to try to quash the rumors of an impending resignation, he apologized for “clearly causing a distraction.”

“I apologize to residents for being in a situation where even we have to be standing here talking about this as opposed to the good work that the council has just completed,” Brown said.

Wednesday, however, could bring a new day of speculation for Brown.

“I’ll be right here working,” Brown told reporters. “Everyone knows, I will be right here working as hard as I can.”