At a Catholic school convention in Perth today, Bill Shorten asks teachers from the private catholic system to vote Labor for Gonski reforms.
Labor has promised $37 billion over 10 years, including $4.5 billion in extra funding in 2018 and 2019, to fully fund Gonski.
The Turnbull government will invest an extra $1.2 billion in schools but seek to impose new conditions on the states and territories to get the money.
Catholic schools receive 83 per cent of the funding that public schools receive. Parents of Catholic pupils fund about 30 per cent of the entire operation of the sector, the conference heard.
Mr Shorten told delegates that his parents had "sacrificed a lot" to send him to elite Melbourne Catholic school Xavier College and that parents who send their children to private schools and Catholic schools have a "legitimate expectation" that their taxes come back in some portion to education funding.
"This is a core value of mine," Mr Shorten said, drawing applause.
Prime Minister Malcolm Turnbull recently suggested the Commonwealth should support the independent and Catholic sectors while the states should be responsible for the public system.
Mr Shorten said the idea would "reignite all the ugly debates about government versus non-government" education to the detriment of the system.