Raleigh, N.C. — A federal judge has ruled that North Carolina's decision to issue special anti-abortion license plates is unconstitutional because the state doesn't offer similar plates supporting abortion rights.

U.S. District Court Judge James Fox ruled on Friday that the state's attempt to offer only the “Choose Life” plates represents "viewpoint discrimination in violation of the First Amendment."

Fox last year blocked the state from issuing the plates while a suit by the American Civil Liberties Union was pending.

Chris Brook, legal director of the ACLU's North Carolina Legal Foundation, said the case is about free speech, not abortion.

"The problem here is the lack of balance," Brook said. "It's a First Amendment issue. If you're going to have this government avenue for private speech, you need to allow speech on both sides of the political debate to occur."

North Carolina lawmakers authorized the "Choose Life" plate in 2011, with a portion of the proceeds from sales of the plates earmarked for a nonprofit that supports crisis pregnancy centers. The law prohibited money from the plates from going to any group that promoted abortion.

Meanwhile, lawmakers defeated various amendments to the bill that created the "Choose Life" plate that would have also authorized plates that would have stated “Trust Women. Respect Choice” or “Respect Choice.”

Rep. Mitch Gillespie, R-McDowell, sponsored the bill for the "Choose Life" plate, and he said Monday that he will encourage the North Carolina Attorney General's Office to appeal the decision.

The Attorney General's Office hasn't yet decided whether to appeal the ruling. Any appeal would go to the 4th U.S. Circuit Court of Appeals, which ruled against a similar license plate law in South Carolina in 2004.

“Every case is different. They could rule differently,” Gillespie said. "There’s a very good debate over whether it’s viewpoint discrimination.”

Twenty-nine states either already make "Choose Life" plates available or have approved such plates but have not manufactured them. But the plates have a mixed record when it comes to court challenges, with some judges ruling states can sell them and others siding with challengers who say the plates are unconstitutional.

North Carolina's two Catholic bishops called Fox's ruling "a tremendous disappointment" and said in a statement that they hope the state appeals the case.

Gillespie said he plans to try again when the General Assembly reconvenes next year to get a pro-life license plate in North Carolina, but he said he's opposed to a "Respect Choice" plate.

"I’d be willing to sacrifice this before I’d be willing to vote for that. Personally, I couldn’t do it,” he said. “My personal convictions on this are strong.”