Gov. Andrew Cuomo signed a labor-backed bill Thursday to help shield public employee unions from a looming US Supreme Court decision, as he works to lock down union support for a third term.

Unions fear the high court may strike down mandatory collective bargaining dues by ruling they violate the First Amendment. A ruling is expected by the end of June.

The legislation will make it easier for unions to register public employees and to impose rules on opting out. It also allows unions to deny benefits, such as free legal representation for job-related issues, to workers who opt out.