A measure that requires union labor for all Honolulu public works projects of $2 million and up is awaiting Mayor Kirk Caldwell’s signature.

The Honolulu City Council passed Bill 37 on Wednesday despite no votes from members Brandon Elefante and Heidi Tsuneyoshi. Councilwomen Carol Fukunaga and Ann Kobayashi voted for the bill but “with reservations.”

If approved by the mayor, project labor agreements will be used for all large public works contracts.

The specifics of the deal would be negotiated with the mayor, according to the bill. The lowest bid is still the winning bid, but the agreement could require nonunion contractors who win bids to hire union workers. It also may require nonunion employees to pay union dues, but it wouldn’t necessarily require them to actually join the union.

Union advocates said PLAs, also called community workforce agreement, can help rein in the use of low bidding out-of-state contractors and promote quality work that is done on budget and on time. Non-union contractors opposed the measure arguing that it discriminates against them and unfairly forces them to pay union dues. They also predicted the measure would increase project costs.

The original version of the bill would’ve required PLAs for projects over $250,000. As an apparent compromise, it was increased to $1 million, which was doubled at Wednesday’s meeting.