A lawsuit that has the potential to reshape the way schools are funded in Pennsylvania cleared another legal hurdle on Monday.

A panel of Commonwealth Court judges swept away some of the state's objections to a suit, brought by plaintiffs including Philadelphia parents and the William Penn School District in Delaware County, that contends Pennsylvania's school funding system is unfair, inadequate, and unconstitutional.

The court overruled a claim by Republican lawmakers that William Penn and the other petitioners had not proven that the current funding system caused harm to students. Judges did, however, say they wanted to hear more information from the plaintiffs — including whether a 2016 funding formula rendered inequalities moot, and information about whether education is a fundamental right.

Lawyers for House Speaker Mike Turzai (R., Allegheny) have argued that students have "no fundamental right to equal education" under the state constitution.

The funding formula does not discharge the state from its obligations, said Maura McInerney, an Education Law Center lawyer representing the plaintiffs along with the Public Interest Law Center. Just 2 percent of all education funding flows through that formula.

As to the larger question, "I think it's very clear to almost everyone other than the legislature that education is an important right," McInerney said. "This is clear in the language of our constitution."

Pennsylvania has the largest gap in funding between wealthy and poor school districts, federal data show.

The funding lawsuit was first brought in 2014. It alleges state officials have "adopted an irrational school funding system that does not deliver the essential resources students need and discriminates against children based on where they live and the wealth of their communities."

The Commonwealth Court judges ordered further discovery by both sides. There is no timetable for when a trial may occur.

McInerney said the case, which could affect more than 1 million children in 500 school districts across the state, is important. "Pennsylvania children are suffering extraordinary harm," she said.