In Plymouth, construction workers turned out regularly at hearings and board meetings last year on a proposed $422 million movie studio, then held a rally outside the Town Meeting where the project won final approval.
 

In Quincy, trade unions lobbied local officials heavily for more than a year in support of two proposed big-box retail stores, which received final approvals early this year. And in Brockton, unions supporting a controversial power plant have held two large rallies and mailed fliers to every home in the city, and now are going door-to-door to sell the project to residents.
 

South of Boston, the recession has triggered a surge in prodevelopment activism among union members hungry for work. Either already jobless, or fearful of losing what they have, the members are pressing officials to approve the few construction projects still on the drawing board.
 

“We have had literally hundreds of members go to hundreds of meetings,’’ said Robert Rizzi, president of the Quincy and South Shore Building Trades Council. “No one expected to see times like this.’’
 

The recession has battered the construction industry, which has seen employment plunge 17 percent nationally in the past two years, according to the US Bureau of Labor Statistics. The downturn followed a run of good times in Massachusetts, which included a surge in construction of homes, stores, and offices, as well as major public works projects that included Boston’s Big Dig.
 

Today, when even small projects go before local boards, union activists are on hand to voice support, according to Steven Winter, senior project manager for the Metropolitan Area Planning Council.
 

“The construction industry is not just in pain, they are bleeding profusely,’’ he said.
 

“We’ll go to meetings of zoning boards, planning boards, and public hearings for projects that will promote work for our members,’’ said Jim Bragg, head of the Brockton-based Carpenters Local Union 624. “We keep an eye on things like new police stations and other public works projects.’’
 

Ed Foley, business representative for New Bedford-based Sheet Metal Workers Local 17 and a leader of the Plymouth movie studio campaign, said union members have been devastated by the recession.
 

“We have members losing their benefits,’’ Foley said. “They have trouble making their mortgages. They can’t send their kids to summer camps.’’
 

Bragg said the unemployment rate for members of his carpenter’s local is about 40 percent.
 

In backing new construction, unions sometimes find themselves at odds with local residents, who fear projects will increase traffic and cause environmental problems. For example, the Brockton Clean Energy proposal for a 350-megawatt power-generating station has put unions in a long-running dispute with neighborhood activists who fear pollution from the plant, which would be fueled by natural gas.
 

Both the unions and the citizens group Stop the Power have lobbied city officials, testified at hearings, and used the media to publicize their positions.
 

“We are canvassing the neighborhoods, trying to educate people,’’ said Gary Sullivan, president of the Braintree-based Utility Workers Union of America Local 369. Of the project’s opponents, he said, “They are a very small group that is well organized, and they are making a lot of noise.’’
 

Ed Byers, a leader of Stop the Power, said the union activists are misguided and are being used by developers and politicians with an interest in the power plant. “The union people are all good people looking for jobs. It’s sad. It shouldn’t be this way,’’ he said.
 

Jim Bosco, a Brockton resident and activist in Stop the Power, said he wishes the unions would channel their activism in support of renewable-energy projects instead of a gas-fired fossil-fuel plant.
 

“I understand the need for jobs. I’m just opposed to the type of construction they’re supporting,’’ Bosco said.

Union leaders maintain that the power plant will not harm the neighborhoods, and they point out that many members don’t live far from the planned facility. “They are not going to do anything that would jeopardize their families just for a job,’’ said Bragg.
 

In Quincy, a series of meetings resolved differences between neighborhood activists and supporters of planned Lowe’s and BJ’s stores in West Quincy, according to Ward 4 City Councilor James H. Davis III.
 

“The unions were respectful of the neighborhood,’’ said Davis, who worked to broker a settlement between the two sides. “They said they wanted jobs but they want something acceptable to the neighbors.’’
 

Sullivan, whose union represents the workers who would run the Brockton power plant, said union members will continue to go door-to-door to build support for the project. City and state officials are reviewing the plant now.
 

“Grass-roots takes time, but it’s the best foundation,’’ Sullivan said.