As Connecticut Governor Dannel Malloy stalls on the announcement of whether he will seek a second term this November, Republican challengers are racing to qualify for public campaign funding under the state’s Citizen’s Election program. But a new campaign finance law passed by Malloy in June could make public funds a smaller part of a candidate’s war chest.

The new rules allow state political parties to make unlimited contributions to publicly funded candidates. Malloy supporters claim the changes will help mitigate the impact of the Supreme Court decision in Citizens United, which led to substantial spending by super PACs and individuals in Connecticut in 2012. Now, parties will be able to respond with similar spending. But advocates for campaign spending regulations charge that the new rules undo some of the progress the Citizen’s Election Program has made in limiting the influence of big money in elections.

Cheri Quickmire, executive director of Common Cause Connecticut, a nonprofit that lobbies for restrictions on campaign financing, said she is concerned about the potential for an influx of spending by undisclosed donors.

“Short of rewinding the Citizens United decision in court, which is something I think would be a good idea, we need to know where that money comes from,” Quickmire said.

The law also doubles the amount that an individual can donate annually to a state party from $5,000 to $10,000. When a party or PAC donates to a candidate, voters can view records of the transaction online, but they can’t see who made the initial contribution.

State Sen. Toni Boucher, who is one of six Republican candidates seeking to challenge Malloy, is trying to qualify for public financing by raising $250,000 in donations under $100. Boucher said she thinks the new law undermines the intent of the public financing system — which she has used in state senatorial campaigns — by strengthening the influence of political parties over that of individual donors.

Meredith McGehee, policy director at the Campaign Legal Center, a nonprofit that analyzes campaign finance laws across the country, said Connecticut’s public financing system gave the state some of the strongest campaign regulations in the nation when it was implemented in 2008. But the June law sapped the strength of those regulations and opened a loophole for greater individual donations, she added.

“State party contributions to candidates can be used as a means of evading individual contribution limits,” she said.

James Hallinan, a spokesman for the Democratic Party, said the party had been fundraising aggressively to counter a predicted influx of spending by outside groups.

“Democrats can never compete when it comes to the super PACs and the Tea Party groups,” Hallinan said. “But we certainly can work very hard and raise our grassroots donations to try and counter it.”

Boucher said she believes the Democrats have also been taking advantage of outside spending, citing a trip Malloy took to California in October.

Chris Cooper, a spokesman for Tom Foley, said his candidate was prepared to match Malloy’s fundraising and additional contributions by the Democratic Party. By the end of the last reporting period, he said, Foley had raised $130,000. Foley has not yet decided whether he will use public financing should he qualify for it.

Gary Rose, chairman of the Department of Government and Politics at Sacred Heart University, said he believes the Republican Party will wait for the primary to conclude before donating to a gubernatorial campaign. He added that the eventual Republican nominee will need a huge amount of money to combat the Democratic Party’s fundraising.

Rose said that because the new law also allows parties to spend as much as they like on legislative campaigns, polarization in the state house could increase. Because candidates will be more reliant on donations from the state party, they’ll hew more closely to the party line, Rose said.

“This is definitely going to strengthen the hand of Jerry Labriola and Nancy DiNardo, the state chairs,” Rose said.

Ten states have public financing systems in place for gubernatorial elections.