Treasurer Steve Grossman and Attorney General Martha Coakley clashed over a proposed campaign finance pact Monday night at the first Democratic gubernatorial forum since the field narrowed from five to three.
Just two hours before the debate, Coakley challenged Grossman and the third candidate in the race, former Obama administration health care official Donald Berwick, to sign a People’s Pledge designed to limit third-party spending.
At the Jamaica Plain forum, Grossman labeled Coakley’s call for a pledge “laughable,” because he had proposed something similar in September and she had declined to sign it. He added that she should not be lecturing the rest of the field, given that state election officials recently found she had violated campaign finance law.
Coakley suggested in September that she would support some kind of a People’s Pledge. But the candidates could not come to an agreement on the commitment. On Monday afternoon, she proposed her own version of the pledge, citing concerns about a super PAC supporting Grossman.
“There’s no lecture involved,” said Coakley, saying she was only concerned about transparency.
Grossman declined to endorse the pledge, but said any political action committees involved in the race should be transparent. Berwick said he would sign the pledge.
Grossman’s sharp tone drew some boos among the roughly 75 people on hand to watch the debate, sponsored by the Ward 11 and Ward 19 Democratic committees and the Latino Democrats of Massachusetts.
Grossman and Berwick trail Coakley by wide margins in public opinion polls.
Delegates to the state party’s convention voted Saturday to put the three candidates on the Democratic primary ballot in September.
Two other candidates, homeland security expert Juliette Kayyem and biopharmaceutical research executive Joe Avellone, did not make the ballot.David Scharfenberg can be reached at david.scharfenberg @globe.com. Follow him on Twitter @dscharfGlobe.