Asylum seekers are being told they will be returned to the Bibby Stockholm on Portland from next week.
The vessel was evacuated in August following the discovery of Legionella bacteria in the water supply. However, the Home Office said all necessary tests have now been completed on the barge.
Letters are being sent to asylum seekers confirming their re-embarkation, although it is understood no exact date has been given yet.
A Home Office spokesperson said: “The Home Office has started to send letters to asylum seekers to confirm the re-embarkation of the Bibby Stockholm and notify them that they will be accommodated on board, following the vessel completing all necessary tests.
“The letters confirm the next steps for asylum seekers and reiterate that all asylum accommodation continues to be offered on a no-choice basis.
“Delivering alternative accommodation sites, such as the vessel, is more affordable for taxpayers and more manageable for communities, due to healthcare and catering facilities on site, 24/7 security and the purpose-built safe accommodation they provide.”
The update comes as a Dorset resident is bringing legal action against the Home Office over the use of the barge, which is docked in Portland Port.
Carralyn Parkes, who lives on the Isle of Portland, is set to ask the High Court for approval to challenge the Government department over the barge, arguing the Government requires planning permission.
Ms Parkes is the mayor of Portland but intends to bring the challenge in a personal capacity.
The hearing is expected to last all day and will take place on Tuesday 10 October in London.
The barge is part of Government efforts to provide cheaper alternative housing for migrants waiting for their asylum application to be processed, with former military sites also converted into accommodation.
Prime Minister Rishi Sunak has made stopping boats crossing the Channel one of his top five priorities ahead of a likely general election next year.