Opposition Leader Bill Shorten has written to every public school principal in Australia as Labor ramps up its offensive against the federal government's education plans.
In a letter co-signed by opposition education spokeswoman Kate Ellis, Mr Shorten reiterates Labor's promise of $37 billion in needs-based school funding over the next decade.
Mr Shorten also steps up the attack against Prime Minister Malcolm Turnbull's suggestion he could hand over public school funding to the states.
It's part of a wider campaign launched by Labor on Wednesday and based on Mr Turnbull's policy to "rip $30 billion out of schools" and back away from public school funding.
Mr Shorten uses his letter to tell principals that Mr Turnbull's plans are an "insult" to dedicated public school staff.
"Ending federal support for public schools would lead to a two-tiered system," he says.
"(It) is one of the worst ideas ever put forward by a prime minister."
Mr Turnbull last week hinted the federal government could step back from public school funding as part of a proposal to fork over a proportion of income tax to the states.
Premiers and chief ministers shot down a proposal to be able to levy their own income taxes to pay for schools and hospitals at a Council of Australian Governments meeting on Friday.
The Turnbull government is not wedded to funding Labor's Gonski model of extra money for disadvantaged schools and argues a new agreement is needed after 2018.
The government maintains spending more money on schools does not result in better results and says Labor's promised funding is "barely credible".
But Mr Shorten says the prime minister's willingness to walk away from public schools shows he is out of touch.
"It's not that Mr Turnbull and his Liberals can't afford to fund public schools, it is that they're choosing not to," Mr Shorten said.
Teachers and their unions have recently stepped up a campaign also calling for the government to stick to the Gonski funding plan.
