Delays to moving asylum seekers onto the Bibby Stockholm barge are now being caused by checks on working practices, Sky News understands.
A Home Office source confirmed reports that fire safety issues did lead to initial setbacks, saying a door had been put on the wrong way round.
But now that has been fixed, there is another hold up because the Health and Safety Executive (HSE) is looking at working practices for port authority workers, they added.
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The barge, which is currently docked in Portland on the coast of Dorset, was supposed to start accepting arrivals last week, but the date was pushed back as more work was needed.
The first people were then due to move on to the vessel on Tuesday this week, but that plan was also held up after last minute meetings were held responding to fire safety concerns.
The 222-bedroom Bibby Stockholm will eventually house up to 500 male asylum seekers who are currently staying in hotels, as the government seeks to cut its accommodation costs while their claims are processed.
But the current plan is to start with 50 people – when the vessel is ready.
The barge will have 24-hour security and accommodate single men only, who will sleep in bunk beds with between two and six people per en-suite room.
Reports of fire safety issues surfaced in recent days, with the Fire Brigades Union claiming the government was taking “a reckless approach to the safety and well-being of both vulnerable refugees and firefighters”.
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What’s it like onboard the Bibby Stockholm?
Asked about the concerns, Prime Minister Rishi Sunak said on Tuesday: “All migrant accommodation has to go through a series of checks and inspections to make sure it complies with regulations. That’s what’s happening in this case.
“This is ultimately about fairness. I don’t think it’s fair that British taxpayers are forking out £6m a day to house illegal migrants in hotels.”
The vessel has attracted a backlash from local Tory MPs as well, with Chris Loder demanding to see safety reports, claiming the barge was going to house double the amount of people it was designed to hold.
Sky News has approached the Home Office for comment.