Quinn Supports Loosening Rules on Campaign Spending by Unions Christine C. Quinn, the City Council speaker and an expected candidate for mayor next year, is supporting a change to New York City's campaign finance rules that would significantly expand the ability of unions, corporations and advocacy groups to spend money on behalf of local candidates. The bill, to be introduced on Monday, would allow those outside groups to work directly with candidates on their internal political communications with members - including phone calls and door knocking tours, although not large-scale mailings - without the costs counting against the candidates" spending limits. Critics said the measure, introduced nine months ahead of what is expected to be a closely contested mayoral race, would effectively outsmart the city's stringent campaign finance system, which tries to rein in spending by interest groups and candidates alike. In a strongly worded statement on Friday, the city's Campaign Finance Board said the legislation "would open a gaping loophole" in the city's regulations, "eviscerate" limits on coordinated spending by outside groups and "allow unions and corporations to operate above the law." "A change of this magnitude has never before been proposed this late in the four-year election cycle," the board said in a memorandum marked "Urgent." But supporters of the bill, including civil libertarians and some of the state's biggest grass-roots advocacy groups, said the measure was intended to guarantee the First Amendment rights of unions and other organizations to speak freely about political matters with their members. "Membership communication is a part of what makes democracy work," said Karen Scharff, executive director of Citizen Action New York, an organization that advocates for public financing of elections and improvements to the state's campaign finance system, among other issues. "Education is a very important role of membership organizations and should not be limited," Ms. Scharff said. Unions and advocacy groups are big political players in New York City, often turning out thousands of members in critical districts to vote on Election Day and supplying candidates with grass-roots support. The proposed legislation, introduced by Councilwoman Rosie Mendez and backed by Ms. Quinn, comes after months of complaints from advocacy groups about a recent opinion by the Campaign Finance Board that classified a broad range of internal political activities by those groups as independent expenditures, subject to significant regulation by the board. Ms. Quinn's spokesman, Jamie McShane, dismissed the critical memorandum from the board as "hyperbolic," and argued that restrictions on spending by the general electorate would remain unchanged. "This Council has put in place the most strict spending limits anywhere in America," he said. City Council aides said that under the proposed legislation, any large-scale mailing of political material to a group's membership - one of the more potent ways that unions mobilize support - would still count against spending limits if coordinated directly with a candidate. But critics of the legislation said it would create a new and weaker definition of "coordination," a change that the Campaign Finance Board says would make it virtually impossible to prove that a mailing was illegally coordinated with a candidate. Even before the legislation is formally introduced next week, prominent civic groups were lining up on either side of it. Common Cause, Citizens Action and the New York Civil Liberties Union support the proposal; Citizens Union is opposed.