Republican leaders hoping to restrict union powers led a rally with about 100 people as Missouri legislators returned to the Capitol.
Lt. Gov. Peter Kinder and House Speaker Tim Jones are pushing a measure that would make Missouri a "right to work" state, where union dues cannot be a condition of employment.
Kinder and Jones joined other Republican lawmakers and conservative activists at a Capitol rally Wednesday just a couple of hours before the scheduled start of the session. Jones has made "right to work" a priority for the session that runs through May 16.
Republican leaders in the Senate don't share his enthusiasm.
And Democratic Gov. Jay Nixon has said he would veto the bill. Lawmakers could bypass Nixon by referring the measure to the ballot.