A new television advertisement calls on politicians to stop talking about the Gonski review and agree to a funding model for education.
The Australian Education Union (AEU) launched its nationwide "I give a Gonski" campaign in Brisbane on Sunday.
It wants the states and the Commonwealth to agree on a funding model for the Gonski reforms before the next Council of Australian Governments (COAG) meeting in April.
AEU president Angelo Gavrielatos said it was a critical time, with the future funding of every school due to be decided within the next 2½ months.
"The time for talk is over. It is now time for action," he said.
"Our politicians have a historic opportunity to reach an agreement that will make a real difference to the level of resources in schools and the education of our children.
"The cost of inaction would be far greater than any investment that's required now."
The Gonski review outlined a new model for funding schools and set an ambitious goal of increasing spending on education by about $6.5 billion.
Schools would be funded on the basis of how many students they had, supplemented with extra loadings for regional and remote schools, as well as those that enrol indigenous students or students with disabilities or poor English skills.
Victoria and Western Australia say the plan lacks detail, which is a threat to achieving the education reforms.
The new ads will run across the nation for two weeks.
As part of the union's campaign launch, parents and teachers were out in force in Brisbane to unveil two buses plastered with pro-Gonski advertising.
They'll be operating around the capital over the next two weeks to raise the issue's profile.
Buses will also be running in NSW.
Mr Gavrielatos said it wasn't just educators who wanted reform.
The union released a poll it commissioned which found 89 per cent believed an agreement on Gonski was urgent.
The Auspoll of 2200 people showed that more than 80 per cent also believed their state or territory government should contribute at least part of the additional funding identified in the review.
And it found extra funding for smaller class sizes and more training and support for teachers were the things Australians wanted most.
The Australian Greens backed union calls for an urgent funding deal.
"It would be a terrible thing for Australia if we did not see the federal government putting a substantial amount of money on the table and getting a strong negotiation with the states in getting more money put in public education as quickly as possible," Greens leader Christine Milne said in Hobart.
Greens deputy leader Adam Bandt said an improved mining tax could fund the education reforms.
"There's no point in coming up with these reviews then putting off funding promises," he said in Melbourne. "What we now need to do is stand up to the mining industry to say to Gina Rinehart, 'You've to pay your fair share'. That way we could start funding public schools right now."