Julia Gillard has questioned whether pressure from the federal opposition is behind Queensland's refusal to sign up to school funding reforms.
Premier Campbell Newman wrote to Prime Minister Gillard last week, saying it would be impossible to agree by the June 30 deadline unless the funding offer was substantially altered.
In reply, Ms Gillard accused the premier of turning his back on Queensland children.
She said Queensland schools will gain an extra $2.5 billion in federal funds, in return for an investment by the state of $1.3 billion.
"Parents, principals, teachers and the broader community will wonder why you persist in refusing this extra money for their schools," she wrote.
"It will be extremely disappointing to Queenslanders if you do not put extra money for schools in (Tuesday's) budget."
She said ignorance about what Queensland stood to gain could not be behind the premier's position.
"Perhaps it is because the Leader of the Opposition (Tony Abbott) or members of his team are demanding you put their political interests ahead of the interests of Queensland children," she wrote.
She also pointed out Queensland schools were outperformed by NSW in every NAPLAN measure across every year level last year.
The Newman government says it holds real concerns that Queensland schools will be worse off under the reforms.
In his letter to the prime minister, Mr Newman accused her of not understanding state funding arrangements and making misleading public statements about the changes.