BUFFALO, NY - Four billion dollars...

That's what state education groups say the governor and the state Education Department have short-changed public schools statewide. In a lawsuit filed in New York City, the groups say millions of children can't get a decent education without the money.

The lawsuit claims that millions of kids these days aren't getting a sound education in public elementary, middle and high schools.

"I suspect that many of them are not in Buffalo, and other high-need areas that are being dramatically underfunded compared to their needs," said Michael Rebell, the attorney for the plaintiffs.

The complaint is led by the New Yorkers for Students' Educational Rights, which is made up of parents throughout the state. Last week, the group filed its claim that the state has short-changed public schools by billions of dollars since 2007.

"New York City's about 40 percent of it, so 60 percent is about $2.5 billion," said Rebell, referring to the rest of the state.

The challenge also claims that the state didn't follow a budget plan from 2007 under the Eliot Spitzer Administration that vowed to increase education funding to schools statewide by $7 billion, over a four-year period.

Gov. Cuomo addressed the lawsuit in a recent appearance on Capitol Pressroom.

The governor said: "The theory of the suit is basically, if we spent more money we would have a better education, if that was true, we would have the best education system in the United States of America. Because we spend more money than any other state in the country. It ain't about the money, it is about how you spend it and the results."

But, those behind the effort believe the state constitution was violated and that billions of dollars are owed to public schools. And, that's what the group is fighting to fix.

"They're delaying this plan forever, so they're not providing the opportunity and the court gave them four years to provide this opportunity, so we're well passed the four years, so that's why we're back in court," said Rebell.

Major educational groups are behind this effort -- from the state School Boards Association to the state Council of School Superintendents. The state Education Department won't comment because of the pending litigation.

In 2007 and 2008, when the recession hit, there were huge cuts to education and the state has an obligation to balance its budget.