The first bill being considered by a Missouri House committee this year would prohibit the payment of union fees from being a condition of employment.
Missouri House Speaker Tim Jones says the liability limits are a priority for the 2014 session.
The 85-69 vote in the House was just three greater than the minimum number needed to pass legislation and 24 votes short of a two-thirds majority that would be needed for a veto override.
Republican Rep. Eric Burlison, of Springfield, says the measure makes Missouri an attractive location for new businesses.
Union members sat silently as the House Workforce Development and Workplace Safety Committee debated the issue that attracted attention from legislative leaders of both parties.