The Service Employees International Union, one of the nation’s most powerful labor groups, last year chopped funding on its push for a $15 minimum wage at fast-food restaurants to the lowest level in four years.

The union poured $13.3 million into the effort in 2017, down from $14 million in 2016 and as much as $23 million in 2014, according to Labor Department filings. The SEIU has been the main organizing force behind the nationwide push for raising the minimum wage.