Teaching unions have sent a unanimous message to the new Assembly government urging it to make school funding its main educational priority.
The four main bodies backing classroom teachers and the two associations representing heads in Wales told TES Cymru that incoming ministers must put finances at the top of their to-do list.
The comments came as Labour decided to form a government on its own after winning half the National Assembly's 60 seats in last week's election - one short of an overall majority.
All four of the main political parties pledged to improve school funding in their election manifestos, with Labour promising to increase spending on education by 1 per cent above the block grant that Wales receives from Westminster.
Teaching unions said they would hold the government to that pledge and added that they wanted to see "real and significant progress" on closing the pound;604 per-pupil funding gap with England.
ATL Cymru director Dr Philip Dixon said the "under-funding" of Welsh schools must come to an end during the next Assembly term.
"All the political parties campaigned for that, so there can be no arguments," he said. "More money must get to the front lines and the funding gap with England must close."
NUT Cymru secretary David Evans said closing the gap had to be the priority. "Regardless of what they have said about funding not having an impact on standards, as far as we are concerned one will follow the other," he said.
The call for funding follows concerns that Labour's spending pledges might not narrow the gap if the block grant from Westminster is cut.
Rebecca Williams, policy officer at Welsh-medium union UCAC, called for local authority education budgets to be ring-fenced to stop money being "siphoned off" into other departments.
ASCL Cymru secretary Gareth Jones called for a national funding formula to allow schools to cover the costs of staffing and delivering the core curriculum.
"We need to get away from the annual uncertainty about school budgets and the battles it causes," he said.
Education played a key role in the election campaign, with all four main parties giving it a prominent position in their manifestos.
But on election night and in the aftermath of the poll there were mixed fortunes for two of the parties' education spokespeople.
Plaid Cymru's Nerys Evans failed to win in Carmarthen West and South Pembrokeshire. But former shadow education minister Paul Davies was chosen as interim leader of the Conservatives after party leader Nick Bourne lost his seat.
The election also saw the Assembly lose three political heavyweights who each had a prominent interest in education, as the Liberal Democrats' Jenny Randerson, Plaid's Gareth Jones and Labour's Jane Davidson all stood down.
Ms Randerson, who was most recently Lib Dem education spokeswoman, became the first backbencher to have a bill become law with the Healthy Eating in Schools Measure 2009, while Mr Jones, a former head of Ysgol John Bright comprehensive in Llandudno, chaired the Assembly's Enterprise and Learning scrutiny committee.
Ms Davidson, meanwhile, served as education minister in 2000-07, during which time she oversaw the scrapping of Sats and league tables in Wales and was the driving force behind the introduction of the revolutionary play-led foundation phase for three to seven-year-olds.
Despite the prominent losses, however, the Senedd will be boosted by some additional educational expertise in the form of Keith Davies, Labour's new AM in Llanelli, who was formerly director of education for Carmarthenshire.
Original headline: Unions urge AMs to put school cash at top of to-do list