Students were sent home from Canberra's Catholic schools on Thursday with a media release endorsing an election promise by Opposition Leader Zed Seselja to increase funding for the territory's non-government schools.

Education Minister Chris Bourke said the commission should not be using children to ''spruik uncosted'' Liberal party promises.

But the commission's chairman, Daryl Smeaton, defended the material and the decision to use students to distribute it because ''they are the people we serve''.

Mr Smeaton said the Canberra Liberals had no involvement in the production or distribution of the flyers and similar material would be sent home for promises made by other parties.

The media release, which Catholic schools printed and gave to students after receiving an email from the commission, said the ''Catholic sector welcomes funding commitment by the Canberra Liberals''.

The opposition has promised, if elected, to progressively increase the amount of money non-government schools receive from the ACT government to 25 per cent of what is spent on government schools.

''This announcement provides a guaranteed funding stream as it will establish an ongoing 25 per cent for Catholic schools into the future,'' the commission's media release stated.

The Commission also sent home an election pack with students earlier this week and yesterday reiterated its intention to run a campaign based around education funding.

But Trevor Cobbold, convenor of lobby group Save Our Schools, accused the Catholic education sector of ''double standards''.

''If an ACT government school did this there would be an outcry,'' he said. ''Catholic schools get roughly 75 per cent of their funding from governments - that is federal and territory funding.

''They're almost fully funded by the taxpayer and yet they are free to electioneer among their parents and gear parents up in terms of how they vote as if they are fully privately funded organisations.''

Dr Bourke said ''it is disappointing that uncosted Liberal political promises were spruiked by the Catholic Education Office directly to students and parents through school newsletters''.

''If instituted, this Liberal promise will work against efforts to address disadvantage in schools across Canberra, including in Catholic schools.

''This should be highlighted to students and parents.''

Mr Smeaton said Catholic schools had done ''nothing wrong'' by using their resources to print the election material. ''There's nothing wrong with sending all sorts of material whether it be about the fete that's coming up or something that comes up every four years and that's the local election,'' he said.

''We tell our parents everything the parties have to offer. We tell them everything but how to vote.

''You'll never see the Catholic Education Commission or the Catholic Education Office endorse a political party.''

A spokeswoman for the Canberra Liberals said the party was ''not surprised'' the commission wanted to inform parents of its policy for ACT non-government schools ''given they're currently the lowest funded in the country''.

''We can't speak for the Catholic Education Office, but they're perfectly entitled to communicate with parents, as does the AEU,'' she said.

''The Catholic Education Office has a responsibility to inform parents about how the alternative governments' policies will affect their school.''