As various proposals for a broader public financing system are floated, members of the mainline Democratic conference in the Senate, as well as advocates that have pushed the measure over the years, are telegraphing they won’t support any agreement they deem watered-down.

If anything, the concerns advocates and liberal lawmakers are raising underscores just how much of a Rubik’s Cube the issue is for Gov. Andrew Cuomo, who faces pressure from the left to push the system through the state Senate, but resistance from Republicans to attaining what would be the ideal system desired by supporters, including Working Families Party.

“We’re encouraged by the renewed interested in Fair Elections in Albany,” said Karen Scharff, the executive director of Citizen Action of New York, who released a statement on behalf of the Fair Elections for New York campaign. “But when it comes to public campaign funding, the details matter. History has proven that half a loaf campaign finance reforms result in failure, and we don’t want history to repeat itself in New York. Public campaign funding systems have been successful in New York City, Connecticut, Arizona and Maine because they provide enough public funds for candidates to run competitive campaigns.”

A variety of potential compromises have been floated in recent days that seem geared toward enticing the Senate Republicans to reaching a deal with Cuomo on the issue.

The potential agreements range from a regional plan that would provide more money downstate, to a phased-in approach that would begin to impact races without incumbents running and would begin in the next election cycle.

“Adequate funding, strong enforcement and starting the system in the next election cycle are necessary for public campaign funding to work for New York State,” Scharff said. “We were glad to see the Senate Democrats and Speaker Silver indicate yesterday that they can’t support a weak system that won’t work. We look forward to working with the Governor and leaders to pass a strong fair elections system this session.”

Advocates remain restive over a March agreement with the Legislature that created public financing for only the state comptroller’s race, which Republican comptroller candidate Bob Antonacci is participating in.

Mike Murphy, a spokesman for the Senate Democratic conference, pointed to a package of measures unveiled this week by lawmakers there, adding such compromises would be difficult to support.

“We unveiled our campaign finance and ethics plan earlier this week,” he said. “The current rumors and speculation circulating Albany do not approach that plan and would be very hard to support.”