WASHINGTON – A measure that would outlaw workplace discrimination based on sexual orientation and gender identity overcame a significant obstacle in the Senate on Monday as seven Republicans crossed party lines and voted to begin debate on the bill.

The vote of 61-30 essentially ensured that the Senate has the votes to pass the Employment Non-Discrimination Act that would prohibit workplace discrimination against gay, bisexual and transgender people.

Final passage, possibly by week's end, would cap a 17-year quest to get Senate support for a similar measure that failed by one vote in 1996, the year Congress passed and President Bill Clinton signed the Defense of Marriage Act.

Sen. Dean Heller, R-Nev., one of the Republicans who voted to open debate, had announced Monday that he would vote yes on the bill, saying that after conversations with voters at home and colleagues in the Senate, he had come to the determination that "supporting this legislation is the right thing to do."

It is the first time that the full Senate has considered a measure that includes protection for transgender people.

The bill will face other crucial tests this week before the Senate can ultimately schedule a final vote to approve it, but the first filibuster test was a pivotal hurdle.

The anticipated vote comes four months after the Supreme Court invalidated a federal ban on recognizing same-sex marriages, and nearly a year after some conservative leaders warned that losses in the 2012 elections exposed the party as being out of touch with much of the country on social issues.

Because of opposition in the Republican-controlled House, passage there seems unlikely. Speaker John Boehner reiterated his objections to the bill on Monday, releasing a statement that said he believed it would invite too many lawsuits.

Federal law prohibits discrimination on the basis of sex, race and national origin. But it doesn't stop an employer from firing or refusing to hire workers because they are gay, lesbian, bisexual or transgender.

The bill would bar employers with 15 or more workers from using a person's sexual orientation or gender identity as the basis for making employment decisions, including hiring, firing, compensation or promotion. The bill would exempt religious institutions and the military.

The Associated Press contributed to this report.