Show business unionists have turned out enthusiastically in the middle of the weekend with promises to support legislation to sweeten California’s film tax credit program.

More than 700 attendees, mostly below-the-line workers, came to the standing-room-only rally at Pickwick Gardens in Burbank — three days after the introduction of Assembly Bill 1839, aimed at overhauling the current incentive program and attracting bigger movies and TV series. Speakers urged the audience to press their legislators on the issue, stressing their assertion that the tax credits are essential to keep productions from being lured out of state.

“We are going to stand with you to make sure Hollywood does not become Detroit,” said Maria Elena Durazo, secretary-treasurer of the Los Angeles County Federation of Labor, who noted that Detroit has seen its status as the automotive industry leader eroded in recent years by government incentive programs elsewhere.

“I’ll be damned if we’re going to stand by and see the last film industry worker here turn out the lights — hell, no!” she concluded.

Steve Dayan, secretary-treasurer of Local 399 of the Intl. Brotherhood of Teamsters, promised that the union would be willing to repeat its 1999 action of encircling the State Capitol in Sacramento with 200 Teamster trucks — a tactic used to campaign for incentives. California legislators first approved the current tax credit program in 2009.

“We are not going to let other states poach our jobs,” he added.

Dayan also pointed out that the rally had attracted the legislation’s authors — Assemblyman Raul Bocanegra and Assemblyman Mike Gatto, who received sustained applause — and stressed that the efforts underline the growing intra-union cooperation between the Teamsters and the Intl. Alliance of Theatrical Stage Employees.

“We are joined at the hips,” Dayan said. “This is our business and we’re going to keep this business.”

Art Pulaski, executive secretary-treasurer of the California Labor Federation, told the audience that the federation does not support tax credits for corporations because of the lack of accountability as to the benefits. “We only support this film tax credit because it creates jobs,” he added.

The rally was chaired by IATSE Local 80 business agent Thomas Davis, who began the event on a somber note by asking for a moment of silence for Local 600 member Sarah Jones — the assistant cinematographer who perished in Thursday’s accident on the set of the Gregg Allman biopic “Midnight Rider” near Savannah, Ga.

“Sarah, you are in our hearts,” Davis said.

The bill, the California Film and Television Job Retention and Promotion Act, would renew California’s tax incentives so it runs an additional five years, through the 2021-22 fiscal year. The legislation has 59 co-authors.

The legislation would lift a $75 million budget cap on productions that are eligible for the program and all network and cable dramas would be eligible. Lawmakers have yet to place a dollar figure on how much would be available each year. Demand for incentives far exceeds supply under the state’s current $100-million per year funding.

Attendees at the rally were handed petitions to send to Sacramento with the missive noting that of 41 big-budget feature films shot in 2012 and 2013, only one was shot in California, and that California’s share of the one-hour TV series market has declined from 64% in 2005 to 28% last year.