On Wednesday, a panel in the Missouri legislature voted 7-3 to adopt a law requiring public employee unions to obtain written consent from state workers before they can deduct dues from their paychecks. Current state labor law allows the unions to automatically the dues money from workers, even those who don’t want to belong to the union.

The statehouse has made several stabs at adopting a version of a “right to work” law. Last month, the state senate approved a broader bill that extends the require to private sector unions as well. Gov. Jay Dixon opposes right-to-work and has twice vetoed such bills in the past. But the advocates are pushing a version that could skip the governor and instead decide the matter through a November voter referendum.

Should it pass, Missouri would become the  25th state to adopt so-called “right to work” laws. Michigan became the 24th state earlier this year. Unions have been protesting the move, dubbing such legislation “paycheck deception“.

The common assumption regarding  such legislation is that without a contractual requirement that they belong a union as a condition of employment, many workers would simply drop out. Hence labor leaders’ fear of such laws — and Big Business support for them.