In a letter sent last week, Ms Berry has also requested further detail on the federal government's proposed school funding policy, with the Education Directorate claiming it needs more information to assess its impact just three weeks before the ACT budget is handed down.

Federal Education Minister Simon Birmingham has written to all Canberra schools to let them know their federal funding allocation under his new policy.

However, the ACT government receives the bucket of funds allocated to territory public schools and distributes according to its own determination of need, meaning what is actually given to individual campuses may differ from Senator Birmingham's estimations.

Ms Berry wrote: "Your letter, rather than assisting to communicate the proposal, is likely to confuse and I ask that you do not again directly communicate with individual government schools."

But Senator Birmingham made no promises about contacting schools and urged Ms Berry "to end the scare tactics".

"I will continue to ensure all schools and their communities have the facts on schools funding," he said.

"Everyone can see for themselves exactly how our plan will benefit their school by visiting education.gov.au/qualityschools and clicking through to the Schools Funding Estimator."

Education ministers met with Senator Birmingham on Thursday to discuss the government's new policy.

Research from public education lobby group Save Our Schools was released on the same day claiming that the new funding deal represented just 40 per cent of what was offered in the original Gonski plan once the new figure was adjusted for inflation.

Senator Birmingham described Thursday's meeting as "constructive": "States and territories can publicly posture about something Julia Gillard promised in 2013, but what Malcolm Turnbull and I are doing – and it's the reason David Gonski stood alongside us a little over two weeks ago – is truly delivering on the needs-based principles of the Gonski review."

Also in Ms Berry's letter was a call for existing agreements to continue for the 39 out of 45 non-government schools in the ACT set to lose funding under the proposed policy.

Under the government's new model, an agreement made between the former Labor government and the ACT's Catholic Education Office will be scrapped by Senator Birmingham in pursuit of a single, nationally consistent needs-based model, representing cuts to that sector's schools.

As well, independent schools assessed as funded above the School Resourcing Standard will have their funds cut or funding growth slowed to reach the standard within 10 years.

An ACT Education Directorate spokesman said the department had "sought additional information from the Commonwealth on a number of matters".

"This includes further information around the proposed re-measurement of Catholics schools' Schooling Resource Standard, and some independent schools, and whether the issue of hidden disadvantage in the ACT is adequately considered in the new funding arrangements," he said.

Senator Birmingham said: "I would encourage everybody to move on from the days and the years of separate deals for separate players in the schools funding wars, and back us in delivering the Gonski report recommendations and ensuring we have a true, consistent, needs-based approach to funding in the future."