AUGUSTA — In an unexpected turn, key Republicans threw their support Wednesday behind having the Public Utilities Commission decide the fate of net metering, a financial incentive for homeowners with solar electric panels that’s strongly opposed by fellow Republican Gov. Paul LePage.

The move cast a shadow over efforts by clean energy advocates and their allies to advance a bill aimed at vastly increasing the development of solar power in Maine.

Rep. Nathan Wadsworth, R-Hiram, the ranking House Republican on the legislative committee that was hearing the solar bill, released a statement calling for the PUC to “stay the course on net metering, protect existing solar customers installers and the 400 jobs tied to the solar industry.”

Net metering is a current provision in Maine law in which utilities credit residential solar panel owners for the electricity they produce. Wadsworth said later that it would be better for the PUC to make any modifications in the net metering rule, instead of having the Legislature do it during the final weeks of the session. The PUC has three members, all appointed by the governor.

Wadsworth’s position was supported by House Republican Leader Ken Fredette, who said in a statement to the Portland Press Herald: “I am concerned at the timing of this proposal. A bill this complex, that significantly impacts ratepayers and the solar industry, should have come to the Energy Committee before now. I support energy solutions that provide stability and protection to ratepayers as well as the 400 jobs tied to the solar industry. And unfortunately, this bill may not accomplish those goals.”

It was a surprise turn of events that coincided with a heavily attended public hearing on the proposed law, which Wadsworth had helped craft and had won the support of Central Maine Power, Emera Maine, most of the state’s solar installers and key environmental groups.

Word of the Republican position led, Rep. Sara Gideon, D-Freeport, who helped fashion an agreement with stakeholders that led to the current bill, to question the eleventh-hour timing and motives. Gideon is the assistant majority leader in the House and a strong solar energy advocate.

“My question for Reps. Wadsworth and Fredette is, do they support consumers, ratepayers and job creators?” she said. “If so, stay at the table and examine the year’s worth of work that is vital to hundreds of people’s jobs and thousands of people’s electricity bills.”

The issue of jobs has come into the debate over solar energy because the vast majority of solar jobs now involve installing rooftop panels on homes, and it’s homeowners who benefit from the net-metering law.

Many states have net metering laws, which require utilities to provide a one-to-one credit to customers on their bills for power they generate and feed back into the grid. But the practice is under fire in other states, and the proposal being heard Wednesday seeks a compromise that would put new solar panel owners under a different compensation system.

The notion of solar energy as a job producer in Maine may seem like a novel idea, but the activity is tracked by trade groups such as The Solar Foundation. Its latest Solar Jobs Census ranked Maine 43rd in the country, with 330 jobs attached to the industry, the largest share of them installers in Cumberland County. Massachusetts was ranked second, with 15,095 jobs.

Advocates say the proposal backed by Gideon and other solar energy advocates could create 800 or so new jobs over five years.

The proposed bill aims to grow solar capacity in Maine from about 18 megawatts today to 250 megawatts in five years, or 2 percent of the state’s power needs. Roughly half of the growth would come from homes and small businesses. Lesser amounts would come from utility-scale projects, community solar farms, and from the commercial and industrial sectors.

The political wrangling was taking place behind the scenes, as roughly 100 people testified on behalf of the bill. The proposal was crafted by a diverse group of stakeholders including solar businesses, municipalities and utilities, as well as Reps. Gideon and Wadsworth. It was negotiated largely by Maine’s Public Advocate, who testified in favor of it on Wednesday.

Gideon and other supporters say they had always assumed that LePage’s opposition would lead to a veto threat if the bill made it out of the committee with a recommendation. The new positions of Republican leadership, however, raise fresh questions of whether solar supporters could muster a two-thirds vote in the Legislature to override the expected veto.

Gideon’s pending bill has urgency this year. Maine has a law saying that the PUC will review net metering rules when solar generation hits 1 percent of a utility’s load. That threshold was crossed last year in Central Maine Power’s service area, on one hot day in August. Gideon said she’s concerned that if the Legislature fails to act, the PUC could take steps that will kill net metering.

On Wednesday, the PUC chairman, Mark Vannoy, testified before the committee to give his views of the bill. While stressing that he was neither for nor against the proposal, he highlighted several concerns with it. Among them was what he saw as the potential for all customers to suffer rate increases if the cost of power over a proposed 20-year contact for solar generators is higher than projected. In the fifth year of the plan, Vannoy said, ratepayers could be paying $22 million more on their electric bills.

That negative outlook contrasted sharply with estimates by Tim Schneider, the Public Advocate. He told the committee that benefits to consumers could total more than $122 million over the 20-year contract period.

The committee has scheduled a work session for Thursday to consider the bill.

Rep. Mark Dion, D-Portland, who co-chairs the committee, said the process would continue and that he expects supporters to have a chance to make a case for the solar bill before the full Legislature.