The Catholic education sector has signed up to the Federal Government's "Gonski" Better Schools funding plan, saying it will "deliver significant increases" in funding for every child in the Catholic system.

The National Catholic Education Commission says it is confident that "no school will be worse off" and is "appreciative of the constructive way" the Federal Government has resolved any concerns.

"The arrangements will progressively deliver increased Commonwealth funding to each state's Catholic education system based on common measures of student need across all education sector," the Commission said in a statement.

The agreement will affect one in five, or 735,403 students currently enrolled at 1,706 Catholic schools across the country.

Prime Minister Kevin Rudd says the agreement means "a big slice" of Australia's education system is now covered by the plan.

"We now have almost two-thirds of the kids in Australia benefitting under the Better Schools plan, which will deliver extra funding and extra resources to government schools, Catholic schools and independent schools in most of the states in Australia," he said.

"But we've still got some who we've got to get across the line."

Western Australia, the Northern Territory, Queensland and Victoria have not yet signed up to the multi-billion-dollar scheme that was spearheaded by businessman David Gonski.

However, the ACT, South Australia, Tasmania and the Coalition government in New South Wales are all on board.

Earlier this month the independent schools sector also agreed to take on the Gonski changes.

PM urges Victoria to get on board

The Government is concentrating its efforts on securing support in Victoria, with the Prime Minister and Education Minister Bill Shorten meeting Premier Denis Napthine this afternoon.

"Our call is pretty basic - come on board Premier," Mr Rudd said.

"This is a great plan for Australia."

The Prime Minister said it would be worth an extra $4 billion for Victoria's education system.

"I'm not sure any mum and dad, or person in charge of a local parent community in a school in the state system in Victoria would want to say goodbye to that," he said.

"Because we want to lift all boats, we want to lift all schools - government, independent, Catholic - that's what we're about."

Later, Victorian Premier Denis Napthine said the discussions were fruitful, but he is still yet to sign up.

"We're happy to work over the next few days to try and get a positive outcome," he said.

"We want a positive outcome on education funding. We also want assurances from the Federal Government with regard to the management of our schools.

"In Victoria it's absolutely vital that our schools are for us, that our schools are managed by local school councils."

Mr Shorten would not comment on whether there had been an extension to Victoria's deadline.

"I think that if we're going to be able to get a good mutual win win for the children of Victoria and government schools, there's no doubt in my mind that we'll know in the next few days," he said.

The $15.2 billion package passed Federal Parliament last month with 65 per cent of the money coming from federal coffers and the rest to come from states and territories.

It will draw $9.4 billion from the federal budget over six years, with the added sweetener of having federal funding indexed at an increased rate of 4.7 per cent.

The states and territories have each been asked to maintain current school spending and commit to 3 per cent growth in school funding every year.