By Ros Krasny
BOSTON (Reuters) - Democrat Elizabeth Warren's claim of Native American heritage was once again in the spotlight as she sparred with Republican rival Scott Brown on Monday in the second debate of the pair's contest for the U.S. Senate seat from traditionally Democratic Massachusetts.
Recent polls show Warren, 63, a Harvard Law School professor and former official in President Barack Obama's administration, maintains a slim lead over Brown, who swept into the Senate in a special election in 2010 after the death of revered Democratic Senator Edward Kennedy.
The debate at the University of Massachusetts Lowell before a sometimes raucous crowd of over 5,000, was combative. The candidates staked out opposite positions on issues ranging from how to create jobs to the timetable for bringing U.S. troops home from Afghanistan.
Brown, 53, repeated his call for Warren to release her personnel records to prove that she had received no unfair advantage by claiming to be Native American. He said the issue was one of "integrity and character."
"I have never used that information ... to get any kind of advantage," said Warren, whose campaign has said she is 1/32 Native American.
Warren said she was told about her heritage by her mother and never saw any reason to question it. "To try to turn this into something bigger is just wrong," she said.
For his part, Brown said he was not guilty of exaggeration when he remarked this summer that he had had "secret meetings with kings and queens" in his role as senator.
Brown termed himself an "independent" several times, citing his moderate voting record and saying that Senate Republican leader Mitch McConnell "will have to work very hard to earn my vote" in the next Congress.
He slammed Warren for not being able to name a Republican senator who she would be able to work with. She finally named Indiana Senator Richard Lugar, who lost his primary fight in the spring to a more conservative Republican.
When Brown lauded "the beauty of being independent," Warren said that "he's sure not saying the same thing when he goes around the country raising money" for his campaign.
Brown's overall record might be centrist but he is "in lockstep" with his party's leadership on key votes involving taxes and economic policy, Warren said.
"On economic issues, I absolutely do" believe that Brown's role is to obstruct Obama's policies, Warren said, citing his votes against various job and unemployment measures.
Her campaign has made Brown's candidacy a national issue and the Massachusetts election critical to which party has control of the Senate after the November 6 election.
Democrats have a 51-47 advantage over Republicans in the 100-seat U.S. Senate, with two independents. However, they are defending more than 20 seats against Republican challengers, while Republicans are defending only half that many.
In Massachusetts only 29 percent of likely voters in a recent survey taken for WBUR, Boston's National Public Radio station, said they would prefer to see Republicans in control; 58 percent say they would prefer to see Democrats continue to run the Senate.
Brown avoided a question on whether he would be "a reliable ally" of Mitt Romney, should the Republican presidential candidate be elected, and whether he was distancing himself from Romney, a former Massachusetts governor, who is forecast to lose the state by a wide margin.
During the testy one-hour debate, moderator David Gregory of NBC asked the Democrat if she felt Brown was "needling" her by routinely referring to her as "Professor Warren."
"It doesn't bother me. I worked hard for this," said Warren, who grew up in Oklahoma, the daughter of a janitor.
Still, Brown drew boos from the audience when at one point he interrupted Warren, saying, "Excuse me, I'm not a student in your classroom. Please let me respond."
Two more debates are scheduled before the election.
(Editing by Christopher Wilson)