Councilor at Large John R. Connolly came under fire from several other mayoral candidates Tuesday after receiving a pledge of support of at least $500,000 in financial support from a national education nonprofit group that supports increasing access to charter schools, lengthening the school day, and providing prekindergarten classes to more children.
In the most strongly worded denunciation, Suffolk District Attorney Daniel F. Conley said Connolly is sullying the integrity of the mayoral race by accepting assistance from an outside group that is not subject to the same spending limits as those who contribute to individual campaigns.
"John is buying into an opaque political shell game that denies voters the simple right to know who is participating in their own election," Conley said in a lengthy statement issued Tuesday afternoon. "It's wrong, and John knows it's wrong."
While he declined to respond directly to the funding issues, Connolly struck back at his critics Tuesday.
"I think Boston voters deserve to hear more than political attacks," the candidate said in a statement. "They want to hear our ideas and vision for the future."
Other candidates, meanwhile, said Connolly's failure to denounce the outside expenditure was telling.
Councilor Rob Consalvo, who has spent much of the mayoral race calling for a ban on outside money, used the announcement as fodder for renewed calls for candidates to take a so-called Boston Pledge, limiting outside expenditures.
"We have an opportunity to send the strongest message possible to say that . . . Boston is not for sale," Consalvo said Tuesday.
The money from Stand for Children would not be donated to the Connolly campaign account, and per federal election rules the candidate cannot coordinate with the group on how the money is spent. The pledged money would be spent directly by Stand For Children on materials, advertisements, and canvassing in support of his campaign.
Under Consalvo's proposed Boston Pledge, based on the People's Pledge taken by US Senate candidates Elizabeth Warren and Scott Brown in 2012, each candidate would be required to make a contribution to One Fund Boston matching any money spent by an outside group on behalf of the candidate's campaign. The fund benefits victims of the Boston Marathon bombings.
Consalvo's proposal has been largely ignored by the other 11 mayoral camps for most of the campaign.
In July, Charlotte Golar Richie told the Globe that she would not sign such a pledge. Just a month earlier, Golar Richie, the sole female candidate in the race, had received the endorsement and some financial support from EMILY's List, a national organization that focuses on electing women to public office.
Other candidates, such as state Representative Martin J. Walsh and Councilor at Large Felix G. Arroyo, have also benefited from cash expenditures on their behalf by outside special interest groups, including labor organizations.
Conley, who on Tuesday became the first candidate to sign on to Consalvo's pledge, said that campaign contributions from special interest groups take decision-making out of the hands of Boston voters and allow corporations to influence the race. "As a point of fact, I've raised a good amount of money in this campaign, and not a single dime of it has come from an outside interest group," Conley said.
The district attorney acknowledged that he was one of a handful of candidates who met with Stand For Children while the group was determining whom to endorse. However, he said it was unknown to him that it was planning to dole out this kind of money and that he had suggested the group favor issue-based advocacy, rather than backing one specific candidate.
If the nonprofit organization had endorsed him and offered the $500,000, Conley said, he would not have accepted it.
Conley vowed that if he is one of two finalists after the Sept. 24 preliminary election to also take the Boston Pledge in the general election if his opponent will agree to take it, as well.
Councilor Michael P. Ross stopped short of saying he, too, would take the Boston Pledge, but he did note the sizable commitment to Connolly in a fund-raising e-mail his campaign staff sent out.
"This is what we're up against: special interests with deep pockets who see that this race is wide open and want to push their agenda," Cayce McCabe, Ross's campaign manager, wrote in a fund-raising e-mail sent Tuesday morning. "That's why we're fighting back from the grass roots."
Wesley Lowery can be reached at firstname.lastname@example.org. Follow him on Twitter @WesleyLowery.