ACT Treasurer Andrew Barr and federal MP for Fraser Andrew Leigh will renew calls for the Australian Charities and Not for Profits Commission to be retained on Wednesday, after government estimates showed how much funding could be saved for non-profit organisations.

Mr Barr said the ACT government would work with the commission, established by the former Labor government in 2012, to end doubling up of bureaucratic processes for charities.

The pair will meet Lifeline Canberra chief Mike Zissler and Lynne Harwood of Communities at Work on Wednesday.

''Only a national regulator can provide a one-stop shop and reduce reporting duplication for charities that work and fund-raise across states and territories,'' Mr Barr said.

''It is impossible for one level of government by itself to reap the full savings benefit that co-operation with the ACNC promised.''

The body was established following a Productivity Commission review of the sector that called for a regulator to take responsibility for deciding which organisations are awarded charity status.

Prime Minister Tony Abbott made a commitment on shutting down the ACNC to September's federal election, as part of a campaign to reduce government red tape.

The Catholic Church is pushing for the commission to be abolished.

Dr Leigh said other states and territories should follow the ACT's lead in better co-ordinating processes to free up time for charities to assist the community.

''We know that the ACNC is enormously popular, with four out of five charities supporting it,'' he said.

Mr Zissler said axing the commission would be a retrograde step.

''We want a one-stop shop for all our reporting,'' he said.

Legislation to axe the regulator will be considered by a Senate inquiry, due to report in June.