The Turnbull government has received a key endorsement for its school funding plan as it makes a big push for Senate support.
With MPs back in Canberra for one last fortnight before the long winter break, the government is keen to pass its $18.6 billion school funding package to give principals certainty over their budgets for 2018.
Former NSW and South Australia education boss Ken Boston, a member of the original Gonski panel, has come out strongly in support of the government's plan, saying the country shouldn't let the historic opportunity pass.
"There are no grounds for opposition to the schools funding bill in principle, and every reason to work collaboratively towards its successful implementation and further refinement in the years ahead," Dr Boston told Fairfax Media on Tuesday.
"It will be a tragedy if the school funding bill is voted down in the Senate."
Labor is firmly opposed to the bill, arguing it is not needs-based or sector-blind and offers schools $22 billion less than it planned.
But Dr Boston says the magnitude of what is within reach outweighs other concerns, including the argument of insufficient funding.
Education Minister Simon Birmingham hopes Senate crossbenchers and the Greens - and ideally Labor too - would heed the latest endorsement of his deal.
"It's an indictment on (Opposition Leader) Bill Shorten to have the likes of Ken Boston out there saying this is fair, needs-based funding and the legislation should pass, yet Labor continues to stand against it," he told Sky News.
But the Greens and most of the crossbenchers appear to be keeping open minds.
"We have a couple of different pathways where this could get through the parliament," Senator Birmingham said.
Nick Xenophon's team of three want more transparency and accountability over the way funding is distributed and to make sure states can't cut their contributions.
"I like to think that with some sensible compromises we can get this through," Senator Xenophon told ABC radio.
Sticking points for the Greens include getting money to the neediest schools faster, making sure the states still do the heavy lifting to boost public schools, and establishing an independent national school resourcing body.
A Senate committee will report on the package on Wednesday and the bill is expected to be debated next week.