JEFFERSON CITY, Mo. -- Missouri's Republican-led Senate on Wednesday advanced a right-to-work bill to ban mandatory union fees that would exempt current contracts until they expire.

Senators voted 21-12, with three Republicans joining Democratic opponents, to give initial approval to the measure. It needs another vote of approval before it can move to the House, which last week passed an almost-identical bill.

The Senate version has a provision that would exempt current union contracts until they're up for renewal, extension or amendment. The House bill doesn't include that provision.

Republican supporters were able to move the bill forward in the Senate without a potentially hours- or days-long filibuster by bipartisan critics. Republican Sen. Bob Dixon, who voted for the measure, afterward said he was "overcome with pride."

The vote came after an emotional speech by Democratic Minority Leader Gina Walsh, who has served as a union president.

"Right to work is wrong for Missouri, and my heart breaks for the working-class families of this state that will suffer under its impact," Walsh told colleagues from the Senate floor. She said that would mean "lower wages, fewer jobs and an irreparable wound upon the fabric of our nation."

She teared up before sitting down.

Walsh told The Associated Press passage of the proposal was inevitable. She said Democrats wanted an opportunity to be heard and propose changes, which were repeatedly voted down.

Right to work is on the fast track in Missouri this year with support from new Republican Gov. Eric Greitens, who has pledged to sign the policy if the GOP-led Legislature sends a bill to his desk. Proponents argue it will bring jobs to the state and give workers the option not to pay into a union.

A Senate vote to send the bill to the House could come as early as today.