Two Democratic candidates for Nassau County executive unveiled endorsements from former congressmen and a labor group this week.

Laura Curran, a county legislator from Baldwin, won the backing of the Enterprise Association of Steamfitters Local 638, a union representing 1,400 workers and the first to endorse in the county executive race.

And state Assemblyman Charles Lavine of Glen Cove has the support of former Reps. Gary Ackerman and Steve Israel, who represented the North Shore in Congress.

Curran, Lavine and Nassau Comptroller George Maragos are in a three-way race for their party’s nomination to seek the county’s top elected office.

In endorsing Curran, Pat Dolan, president of Steamfitters Local 638, said she has been a “vocal advocate for organized labor” as a county legislator.

“Laura has stood with us whenever we needed her to and that’s why today, and throughout this campaign, we’re standing with her,” Dolan said in a statement.

Curran also has backing from the Nassau County Democratic Committee and state Sens. Todd Kaminsky and John Brooks.

Ackerman, who represented Queens in Congress from 1983 to 2013, and Israel, who represented Long Island’s 3rd Congressional District from 2000 until last year, touted Lavine’s commitment to progressive values in endorsing him.

“When we represented the same communities, I was truly impressed by his tireless efforts to support our veterans and the environment, to fight for a strong middle class, as well as equal pay for equal work and reproductive rights for women,” Israel said in a statement.

Lavine also has the backing of the Assembly’s top two Democrats, Speaker Carl Heastie (D-Bronx) and Majority Leader Joseph Morelle (D-Utica).

Hank Sheinkopf, Maragos’ head political strategist, downplayed Curran’s and Lavine’s endorsements, noting that neither Ackerman nor Israel live in Nassau County.

“The problem is endorsements don’t vote, people do,” Sheinkopf said.

The Democratic primary winner will take on a to-be-named Republican candidate.

Current County Executive Edward Mangano, a Republican who has pleaded not guilty to federal corruption charges, has not said whether he will seek re-election.