The first 50 asylum seekers will be moved to the Bibby Stockholm barge in Portland later, the BBC has been told.
Up to 500 men aged 18-65 will be housed on the barge while they await the outcome of their asylum application.The floating accommodation block was docked off the Dorset coast nearly three weeks ago, and has been empty since due to health and safety worries.
But ministers have said the vessel is safe and functional.
Home Office sources have said the barge is ready to host its first group of asylum seekers, and the BBC understands that some people were told to expect to be moved on Monday.
The government has said the vessel offers basic and functional accommodation and it previously housed oil and gas workers – as well as asylum seekers in other countries.