AUGUSTA, Maine — The former assistant leader of the House Democratic caucus has signed on to a Republican bill that would repeal the law allowing the Maine State Employees Association to deduct the equivalent of union dues from the paychecks of state workers who choose not to join the union.

Rep. Terry Hayes, D-Buckfield, will be the only Democratic co-sponsor of the bill, LD 786, proposed by Rep. Lawrence Lockman, R-Amherst. The bill is one of two pieces of legislation Lockman is introducing this legislative session in hopes of making Maine a right-to-work state. Lockman’s other proposal would allow an employee to work at a unionized, private-sector business without having to support the union financially as a condition of employment.

Hayes said she doesn’t think the provision allowing the Maine State Employees Association, the union that represents most state employees, to collect dues from nonmembers belongs in state law. Such a provision ought to be negotiated as part of a labor contract at the bargaining table, she said.

“I’m a staunch supporter of collective bargaining, and I’m a staunch critic of labor and management doing an end run around collective bargaining by coming to the Legislature,” said Hayes, a former member of the MSEA and the Maine Education Association.

Hayes was the assistant Democratic leader in the House during the last legislative session, from 2010 to 2012, and she was an unsuccessful candidate for House speaker for this session. Hayes has developed a reputation for breaking ranks with her party. Last week, she was one of nine Democrats to buck party leadership and vote against a temporary measure to shield the personal information of concealed weapons permit holders from public records.

The “ fair share provision” became state law in 2007 as part of a bill that also guaranteed public- and private-sector workers couldn’t be required to join a union and protected non-union members from being fired for not paying union dues.

“For me, the process is a key element here, if no-member fees are being charged as a result of legislation and not as a result of a bargaining agreement,” Hayes said.

But Chris Quint, MSEA’s executive director, said the state law simply governs a provision over which the union and management in state government can bargain.

“It’s an issue that is bargained in good faith by both sides,” he said. “Not every union has it in their contract. It is still a bargainable issue, and that’s where it needs to remain, at the bargaining table, not the Legislature.”

While the fair-share provision only became state law in 2007, Quint said, the MSEA has had the provision in its contract since it first gained the ability to collectively bargain under Gov. James Longley in the 1970s. Non-union members are covered under the contracts negotiated by MSEA and have all the rights of union members, save for the ability to vote on union contracts, he said.

The MSEA has nearly 9,000 regular members and receives fees from nearly 2,700 workers who don’t belong to the union, according to Quint.

“These issues that are bargained have been in statute for years, and they are bargained in good faith,” he said. “Just because these things are in the law doesn’t mean they have to be in the contract.”

Hayes said she doesn’t fully embrace Lockman’s bill — she opposes a provision in it that would remove the obligation for a union to represent all workers, union members and nonmembers, at the bargaining table, for example — and she has “no idea” whether she’ll support his other proposal related to unions in the private sector. But in general, Hayes said, she thinks unions should have to prove their value to workers rather than be able to automatically collect union dues from nonmembers.

“I personally believe that any union should have to demonstrate its value and membership should be optional, even though I understand that if there is a union in the workplace that there is an obligation that the union represents all of the employees of that organization,” she said. “If you impose a fee on nonmembers, you diminish the opportunity for union leaders to have to demonstrate the value to their members.”

Lockman has pitched his two right-to-work bills as measures that would make Maine more competitive in attracting jobs. In a news release announcing his right-to-work legislation, the House Republican office cited a study from the Mackinac Center for Public Policy showing employment grew 71 percent in right-to-work states between 1980 to 2011, while states without right-to-work grew 32 percent in the same time period.

In addition, nine of the top 10 states in Forbes’ 2012 ranking of the best states for business are right-to-work states. Maine has ranked 50th on that survey for three consecutive years.

“Half of the country is now right-to-work, and unless Maine joins this wave of economic growth, we will be left behind to pick up the scraps,” he said in a statement issued last month.

Lockman’s bills are similar to two proposals introduced during the last legislative session when Republicans held majorities in the House and Senate. Neither of those bills succeeded. Their chances are likely more slim this year with Democrats back in the majority.