TRENTON - The Newark archdiocese and two parishioners are suing the state over a new law that makes itĀ illegal for the archdiocese to sell headstones and monuments at its 11 cemeteries.

The suit was filed Monday in federal court in Newark by the Virginia-based Institute for Justice.

In court papers, the group's lawyers argue the law is unconstitutional because they say it is economic protectionism that stemmed from lobbying by the Monument Builders Association of New Jersey.

The association lost a 2013 lawsuit in which it claimed the church's tax-exempt status and relationship with parishioners gave it an unfair advantage.

Lawmakers passed the measure in 2014.

They later agreed with Gov. Chris Christie to delay its implementation until 2016. The suit seeks to block its enforcement.