Three Republicans joined all Democrats to advance a bill to bar discrimination against gays and lesbians at work on Wednesday, adding momentum to a measure that Senate Majority Leader Harry Reid has vowed to bring to the Senate floor.

Republicans Mark S. Kirk of Illinois, Lisa Murkowski of Alaska and Orrin G. Hatch of Utah joined Democrats on the Senate Health, Education, Labor and Pensions Committee to approve the Employment Non-Discrimination Act, 15-7.

The legislation, championed by Sen. Jeff Merkley, D-Ore., has more than 50 co-sponsors but likely would need 60 votes to break a procedural filibuster. Backers are even closer to that magic number after Wednesday, however, as Hatch and Murkowski are new supporters. Other Republicans who are considered potential supporters include Sen. Jeff Flake, R-Ariz., who voted for the measure as a House member.

Three Democrats — Bill Nelson of Florida, Mark Pryor of Arkansas and Joe Manchin III of West Virginia — have so far declined to sign on to the bill.

Though Reid has not scheduled a Senate vote, sources tracking the bill have indicated since it was introduced in May that it likely would get fall floor time.