The Group of Eight and TAFE Directors Australia, the body representing public VET providers, have formed the "strange fellowship" to lobby federal and state governments to recognise the importance of their sectors in the "Melbourne Declaration", a charter laying out the nation's priorities in education.

Vicki Thomson, chief executive of the Group of Eight, and Craig Robertson, chief executive of the TAFE peak body, are on Friday attending a forum with the nation's education ministers that will examine how to update the charter, created in 2008.

In a joint opinion piece for The Sydney Morning Herald and The Age, Ms Thomson and Mr Robertson have described the opportunity to be involved in the review as a "glimmer of understanding that post-secondary education should be included".

The two organisations have declared that their sectors are not competitors and warned that the uncapped, demand-driven system for university funding had damaged TAFE by distorting the tertiary education market.

"We are different in what we deliver and TAFE supplies an essential component of post-secondary education that is critical to the economy and it has been damaged by education policy. That must be redressed," Ms Thomson and Mr Robertson said.

The pair warned of "inequitable funding and regulatory arrangements" in the system and "unintended consequences" of university places being uncapped between 2012 and 2017.

"Not least of those has been that it created a vast chasm in the community psyche between universities and TAFE," they argue, criticising the decision not to introduce the demand-driven system for all post-secondary education.

"All too soon we were confronted with too much anecdotal information to ignore that schools and parents were, subtly or otherwise, pressuring school leavers into university, with any other study choice seen as second best. But TAFE never was second best."

The intervention on the demand-driven system is notable given the Group of Eight supports the policy because it allows universities to enrol more students and receive more public funding.

The former Labor government uncapped places in 2012. The Coalition then froze demand-driven funding at the start of 2018.

In their opinion piece, Ms Thomson and Mr Robertson say any return to uncapped places must ensure "the post-school system can be directed to where need is most acute" and that students can make a choice based on their interests.

They say all education sectors need to flourish otherwise the economy suffers, restricting opportunities and bringing down living standards.

Labor has pledged to return to the demand-driven system for universities and increase support for TAFE. While the Coalition has frozen funding for universities, the VET sector is widely seen as the "poor cousin" in education due to its funding and regulation.

A deepening stoush over school funding may derail the Melbourne Declaration review, however, with Victorian Education Minister James Merlino and Skills Minister Gayle Tierney boycotting the forum that will be held after a meeting of the COAG education council.

Mr Merlino said he was not prepared to sit in a room and discuss a vision for national education with federal Education Minister Dan Tehan, a man he accused of intentionally setting up a "disgraceful funding model".

"You need to fund education properly and fairly before you earn the right to hold this important forum," he said.

Victoria is the only state that has refused to sign up to the five-year school funding table put forward by the Morrison government, instead signing up to a short-term deal.

Mr Merlino said the federal government wanted to fund public schools less than private schools, and he’d be highlighting this issue by visiting schools in marginal seats.

The Victorian Labor government is also developing an advertising campaign to highlight the discrepancies in funding for state and private schools.