Independent spending by unions and other groups with a stake in the mayoral race has reached almost $5 million, with more than half the cash intended to boost Bill Thompson's bid, according to city Campaign Finance Board records.
United for the Future, a group funded by the United Teachers Federation union, has poured $2.6 million into efforts to get Thompson elected, paying for television and print ad buys as well as mass mailings.
The Democratic former comptroller has also benefitted from more than $183,000 in spending by UFA State Fire PAC, funded by the Uniformed Firefighters Association; and tens of thousands of dollars from two other groups.
The $2.9 million in proThompson funds come on top of the $4.7 million spent thus far by the campaign itself. A Thompson spokesman declined to comment, and a UFT spokeswoman said the union does not comment on independent expenditures.
Overall independent expenditures -- spending by special interest groups operating apart from the campaigns themselves -- was at $4.8 million in the mayoral race as of Friday, according to records. Campaign Finance Board spokesman Matthew Sollars said he expects still more spending will be reported before Tuesday's primary.
Democrat Christine Quinn saw more spent opposing her candidacy than supporting it. A coalition of animal rights activists and labor members, NYC is Not for Sale, has spent $768,737 on leaflets, television ad buys and more urging voters to choose "Anybody But Quinn." Union-backed groups including Hotel Workers for a Stronger Middle Class, meanwhile, have spent $677,688 for her.
Democratic front-runner Bill de Blasio has had $12,830 spent on his behalf compared with $382,049 for Democrat John Liu has $382,049 and $120,001 for Republican front-runner Joe Lhota.
This mayoral campaign is the first since the 2010 U.S. Supreme Court's Citizens United ruling, which found political independent spending by corporations and unions could not be restricted.
The decision did not apply to the city, but it did encourage special interest groups to spend more here, Sollars said. "It changed the political equation in that it raised the profile nationally of what independent groups can do," he said.