A bill that seeks to end workplace discrimination based on sexual orientation and gender identity cleared a critical hurdle in the Senate on Monday, with 61 members voting in favor of moving to a final vote. A vote on final passage could come as early as tonight.

With all 55 Senate Democrats backing the Employment Non-Discrimination Act (ENDA), passage hinged on Republican support.

On Monday, Nevada Senator Dean Heller announced his support, making him the critical 60th vote needed to avoid a filibuster on the Senate floor.

Heller said in a statement that he was backing the measure because “discrimination must not be tolerated under any circumstance.”

The legislation looks to be dead-on-arrival in the House after Speaker John Boehner, a Republican from Ohio, reiterated his opposition.

Boehner “believes this legislation will increase frivolous litigation and cost American jobs, especially small business jobs,” a spokesman said Monday.

On Sunday, President Barack Obama called on Congress to approve ENDA.