The National Disability Insurance Scheme (NDIS) is being accused of blocking people from taking part in the program, despite it being uncapped.
The ACT Government said the Commonwealth agency rolling out the NDIS had told people in Canberra with disabilities it would not meet with them.
It was originally estimated 5,075 people in the territory would eventually be eligible for the scheme. That number has already been reached.
It appears the National Disability Insurance Agency (NDIA) recently told individuals or groups no new planning meetings would be taking place — something that would be unprecedented under the unlimited program.
It is unclear how many people were affected.
Director-general of the ACT Community Services Directorate Michael De'Ath said "it was recently brought to the attention of the Community Services Directorate that the NDIA was advising clients that no new planning meetings will be undertaken in the ACT".
The Federal Government and NDIA have not denied such a directive went out.
But Federal Social Services Minister Christian Porter said meetings were continuing.
"Participant planning sessions are continuing while we await the outcome of the ACT election [this Saturday]," Mr Porter said.
The entire ACT was a trial site for the NDIS, which is now being set up nationwide and is soon set to cost $22 billion annually.
Who pays for the extra participants?
A fight is now brewing between the two governments about which pays for the extra participants.
"The ACT NDIS bilateral agreement outlines a target of 5,075 ACT participants, with the clear understanding that the Commonwealth Government accepts the full cost for any participants beyond this figure," Mr De'Ath said.
"The NDIS is not a capped scheme. All eligible people with disability are entitled to become participants and receive a plan and a funding package."
But the Commonwealth said it wanted a new deal with the ACT.
"The NDIS is not a capped program and so following the ACT election, governments will agree on arrangements for bringing in additional participants," Mr Porter said.