DOVER  — A conservative group is taking its fight against a Delaware campaign finance law to the U.S. Supreme Court.

Attorneys for Delaware Strong Families filed a petition last week asking the court to hear the case.

The group is challenging a 2012 law regarding third-party entities working independently of political candidates to influence elections.

The law requires groups that spend $500 or more during an election period on third-party advertisements to disclose the source of donations. Those advertisements include communications, such as DSF's voter guide, that refer to clearly identified candidates, even if they don't urge a vote for or against them.

A federal judge granted an injunction in 2014, saying the law appeared to be unconstitutional, but an appeals court overturned that decision last year and sided with state officials.