THE SENATE WILL SHORTLY have a chance to approve legislation that would end workplace discrimination based on sexual orientation and gender identity. The proposal has been debated in various forms for nearly three decades, yet never enacted, so the upcoming vote marks an important waypoint in the struggle for gay rights.

We urge the Senate to approve it. There is little chance it will clear the Republican-controlled House this session, but a positive vote in the Senate would provide real momentum for the future.

The Employment Non-Discrimination Act goes to the heart of a core value — that people who work hard and perform well on the job ought to be rewarded based on their work and nothing else. The legislation would extend employment discrimination protections that now cover race, religion, gender, national origin, age and disability to include sexual orientation and gender identity. It would prevent employers and labor unions, among others, from using sexual orientation or gender identity as the basis for decisions such as hiring, firing, promotion or compensation.

When senators consider the measure, we hope they will realize that such protections are already embedded in the workplace policies of many large companies around the country. They should take note that 21 states and the District have outlawed discrimination on the job based on sexual orientation, and 17 states plus the District have laws guarding against bias based on gender identity. We assume that the senators will also be mindful of polls that show there is strong public support across the political spectrum for the idea of discrimination-free workplaces.

The bill addresses most of the major objections: There is an exemption in the legislation for religious groups; nothing in the bill would create quotas or provide for preferential treatment; the bill is not retroactive and does not apply to business with fewer than 15 employees.

Some Republicans have expressed worry that the legislation might lead to a flood of new discrimination complaints and legal burdens for employers. They ought to look at the Government Accountability Office letter of July 31, which tracks the experience, from 2007 to 2012, of states that have such laws. The agency found “relatively few employment discrimination complaints based on sexual orientation and gender identity.” The GAO’s data also showed that the level of complaints at the state level remained pretty much the same over the five-year period, suggesting that a federal law might not unleash a wave of complaints.

Senate Majority Leader Harry Reid (D-Nev.) has the backing of all the Senate’s Democrats and a handful of Republicans, but he may still be short one vote of the 60 needed. This legislation has been introduced in every Congress since 1994 save one. It was originally championed in the 1970s. So much has happened in the past few years to advance the cause of equality for lesbian, gay, bisexual and transgender people — including the growing acceptance of marriage rights — that it makes very good sense to ban workplace discrimination too. The Senate should not miss this chance to take a stand for it.