The jockeying over where and when U. S. Senate candidates Scott Brown and Elizabeth Warren will face off in a series of debates grew a little more complicated Friday as the wife of the late Senator Edward M. Kennedy '54-'56 invited the opponents to a high-profile televised debate in September hosted by Tom Brokaw.

The invitation from Victoria R. Kennedy proposed that the two candidates for the seat that her husband held for more than 40 years face off at a debate at the University of Massachusetts Boston on Sept. 26. The event would be co-sponsored by the Edward M. Kennedy Institute for the United States Senate and the UMass Boston and would be moderated by Brokaw, longtime NBC news anchor.

Warren accepted Kennedy’s invitation on Monday in a press release. Citing the legacy of the late senator, Warren's campaign manager Mindy Myers said the debate was an important part of the Senate race.

“Since this contest is for the office Senator Kennedy held for close to half a century, it is appropriate the candidates honor his memory and many accomplishments by debating the real issues facing working men and women in Massachusetts,” Myers said. “Elizabeth hopes that Scott Brown also accepts this important debate.”

Brown, who currently holds the seat, had yet to accept the invitation at press time. In 2009, Brown beat Massachusetts Attorney General Martha M. Coakley in a special election following Kennedy’s death.

“Everything is under consideration,” Brown spokesman Colin Reed wrote in an email. “Scott Brown has already committed to four debates, including two radio forums that Elizabeth Warren has refused to accept.”

The debate over debates has been in and out of the news since Warren, a Harvard Law School professor, earned the near-unanimous endorsement of the Democratic Party at its state convention June 2, setting up her contest with Brown. The back-and-forth has provided an opportunity for the dueling camps to trade barbs without having to address major campaign issues in recent weeks.

Both candidates have agreed to two yet-to-be-scheduled televised debates: one hosted by WBZ-TV of Boston and one by a consortium of out-of-state media outlets.

Warren has committed to an additional televised debate and Brown to two radio debates.

Both campaigns have said in the past that they hope to participate in about four debates. The EMK Institute-UMass Boston debate would likely be the most visible, since Kennedy proposed airing it nationally on MSNBC.

In a letter to the candidates on Friday, Kennedy, who chairs the EMK Institute, wrote that the two institutions are “in a unique and ideal position” to host such a debate. “The EMK Institute is non-partisan and committed to educating our public about our government—especially the United States Senate—with an eye toward invigorating public discourse,” she wrote. “UMass Boston, the only public university in the city, is dedicated to opening the doors of educational opportunity.”

—Staff writer Nicholas P. Fandos can be reached at nicholasfandos@college.harvard.edu.