With U.S. labor unions under constant conservative fire, the proposed merger of the Screen Actors Guild and the American Federation of Television and Radio Artists is being closely watched within the labor movement as a measure of how unions react to the changing landscape.

“If this is approved, it’s going to be a huge shot in the arm for the labor movement,” AFTRA president Roberta Reardon told Variety on Sunday. “Labor unions have been under attack, particularly with the growing power of corporate employers and their ability to get around unions in new areas of work.”

Members of SAG and AFTRA began receiving ballots Feb. 27 and must return them by March 30. Each union must receive at least 60% support among those voting for the combo to go through.

Merger backers — led by Reardon and SAG prexy Ken Howard — assert that the merged SAG-AFTRA would increase bargaining strength, resolve jurisdictional questions and represent a first step toward combining the health and retirement plans in order to solve the problem of performers not qualifying for coverage under the separate SAG and AFTRA plans.

Reardon’s attending the AFL-CIO executive council meetings in Florida this week as a VP of that group, which provided manpower in the 2003 merger attempt.

“The AFL-CIO is painfully aware of the kind of friction that can occur internally when two unions are seeking jurisdiction over the same work,” Reardon said. “It’s no secret that SAG and AFTRA have had that kind of struggle.”

The anti-merger forces have filed a lawsuit to block the vote count, alleging that the guild hasn’t adhered to its rules in sending out the proposal to members. They contend that the combined union will dilute the power of actors since the new entity will be repping AFTRA’s broadcasters, singers and newscasters — and that merging the pension and health plans is potentially damaging to SAG participants.

Reardon, who’s attended dozens of member meetings on the issue, asserts that she’s cognizant of those concerns.

“The unknown is very scary,” she said. “But having a united consolidated strategy is really critical as the industry gets more complicated. On a show like ‘Glee,’ for example, the actors are represented by SAG but their singing is covered by AFTRA.”

Reardon’s planning to attend a March 17 gathering in Los Angeles followed by an actors federation gathering and an AFTRA board meeting in Los Angeles on March 24.

A hearing has been set for March 26 in Los Angeles federal court on the anti-merger suit filed by Martin Sheen and 60 other actors. The action alleges SAG and its leaders are attempting to merge “without conducting the necessary due diligence”; SAG has labeled the suit “a clear attempt at circumventing the will of the membership” and “a public relations stunt.”

Howard said Sunday that he’s optimistic the merger will be approved.

“Of course the labor movement is watching this carefully because the entertainment and media industries are two of the most vibrant industries in our country, and SAG-AFTRA would be the largest, most powerful union covering those industries,” he said. “Naturally they’re waiting to see what our members decide, and I’m confident they’re going to vote to approve the merger.”

Howard had to skip the meeting in Florida due to an acting gig.

“I’m extremely proud to serve on the AFL-CIO executive council, and I’m disappointed that I had to miss this week’s meeting, but my ‘day job’ as an actor couldn’t be ignored,” he said. “In the midst of this tremendous effort to bring SAG and AFTRA together, it’s important for me to stay engaged in the work that our unions are all about because it helps me be a better leader.”