Peace activists say they are being blocked from marking Remembrance Day with a peace vigil outside the Australian War Memorial by the National Capital Authority.
The Medical Association for the Prevention of War wrote to the authority to inform it of its intention to mark the hundredth anniversary of the armistice to end World War I.
The organisation wants to stage a "silent commemoration" on Anzac Parade outside the war memorial, with the message "honour them – promote peace". A similar event was held on Anzac Parade last year, across the roundabout from the memorial but in view of the main event.
On September 19 the National Capital Authority told the organisation its vigil would not be allowed, saying Anzac Parade was "reserved exclusively for the 2018 Remembrance Day commemorations".
The memorial's director Brendan Nelson responded to the association's media release in an email to the association's president Sue Wareham.
"You and your colleagues are welcome to join the thousands of Australians here at the Australian War Memorial on Remembrance Day remembering our dead and maimed in support of a peaceful world," Dr Nelson said in an email seen by Fairfax Media.
A war memorial spokesman didn't say if it had been consulted by the National Capital Authority in making the decision.
"Anyone who wants to pay their respects to the dead and maimed, and express their support for peace, is welcome to join thousands of Australians who will be honouring them here at the memorial at the Remembrance Day national ceremony," the spokesman said.
Dr Wareham said the group didn't want to take up the invitation to be part of the main ceremony as members wanted to mark their opposition to the war memorial's sponsorship relationships with weapons manufacturers.
Despite the likelihood that the association's protest would only be a small number of people, the National Capital Authority's spokeswoman reiterated to Fairfax Media that Anzac Parade had been reserved exclusively by the war memorial.
"Once an event booking is confirmed, the venue is then not available to be reserved by another event organiser," the spokeswoman said.
Dr Wareham said her organisation had notified the authority due to the large crowds expected on the day and the wish to avoid any disturbance or issues with police.
"The thing we wanted to avoid was us turning up with no official approval and having a kerfuffle with the police," Dr Wareham.
The association, which is the parent body for Nobel Peace prize winners the International Campaign Against Nuclear Weapons, is yet to decide what it will do on November 11 after the setback.
"Our priority is to retain a respectful presence," Dr Wareham said.
