Educators, local officials and parents have complained for years that the formula used by the state to fund local schools is not enough to properly educate students.

Dozens of other state and local leaders will join teachers, labor officials and parents at a rally Wednesday urging the Legislature to finally give school funding a significant boost.

Advocates, the governor, the House leadership and the Senate agree that funds for special education, English language learners and other areas need to go up. But there's disagreement in just how much the state can afford over the next few years without raising taxes.

"We have been shorting districts by millions of dollars over the last quarter. Billions of dollars, in fact, over the last quarter century," said Sen. Sonia Chang-Diaz, the sponsor of a bill preferred by the Senate that would end up putting between $1 billion and $2 billion into schools. "So we're talking about here is not even really new money. It's talking about filling in a hole that we have left unfilled for the past quarter century."

But Gov. Charlie Baker and the moderate House might balk at that price tag and commitment to keep it up year after year.