A union steel worker holds up a sign during a rally outside the Capitol in Lansing, Mich., on Dec. 6, 2012. (Carlos Osorio/AP)

Michigan union activists are protesting outside the Capitol in Lansing as controversial "right to work" legislation becomes law.

Police are expecting up to 30,000 protesters, including both union opponents and "right to work" defenders, the Detroit News reports. The Republican-controlled legislature is expected to reconcile their two versions of the union limits today and send a bill to Gov. Rick Snyder (R).

Access to the building is being limited, police say, to avoid a repeat of last Thursday, when protesters tried to rush the state Senate chamber and were pepper-sprayed.