At least another three years are likely to pass before Launceston's historic Paterson Barracks is repurposed and new cadet facilities are built at Youngtown.
A Defence Department spokesperson confirmed construction of the new facilities has been scheduled to begin in 2022 or 2023.
That'll be about six years and two elections after the federal government announced new facilities would be constructed and the Paterson Barracks would be opened up to the public.
The spokesperson confirmed a detailed business case, which has been in development since at least April last year, was still being worked on.
"The detailed business case is expected to be completed in the fourth quarter of 2020," the spokesperson said.
"Defence is scheduled to table the detailed business case for the government's consideration in early 2021...subject to government and parliamentary approvals, Defence is scheduled to commence construction activities relating to the relocation of Paterson Barracks unit and new cadet facilities in North Launceston in 2022-2023."
Labor Senator Helen Polley criticised the government's handling of the projects and raised concerns about delays.
"The government needs to explain what has taken so long, it is not good enough that three years later we are still yet to hear specific details but there are possible completion dates of four years from now," Senator Polley said.
"This falls squarely at the feet of the Morrison Government's handling of this, once again we find it is all spin and no substance with this lot.
"There are serious questions which need to be answered by the Minister here."
Bass MHR Bridget Archer said the relocation of Paterson Barracks was complex, but on-track.
"I had a briefing from the Minister's office a week or so ago on a number of projects that fall within the City Deal, including the relocation of the Paterson Barracks which is on track to be delivered in 2022-23," Ms Archer said.
"A current business case for the relocation is under development to ensure the complex relocation is done correctly, benefiting the city and those who will utilise the cadet facilities.
"Together with the recent signing of a $30 million defence precinct agreement this relocation is another exciting step forward for our region."
Because the Paterson Barracks relocation and build of new facilities at Youngtown were estimated to cost $30 million or more, the Defence spokesperson said a two-stage capital works approval process was required to be undertaken by law.
"The first stage approval process involves a strategic assessment and the development of an initial business case," the spokesperson said when asked about the projects' timeframes.
"It also seeks government's in-principle agreement for a capital works project and secures the necessary funding to develop a detailed business case for further consideration by government."