As Georgia shovels out billions in economic incentives to electric vehicle manufacturers and other companies, the state’s ruling Republicans are moving to make it harder for workers at those firms to join labor unions, in what could be a violation of current federal law.

The state Senate voted 31-23 on Thursday for a bill backed by Gov. Brian Kemp that would bar companies that accept state incentives from recognizing unions without a formal secret-ballot election. That would block unions from winning recognition from a company voluntarily after signing up a majority of workers, in what is usually known as a card check. Senate Bill 362 moves to the House for more debate.