The transport minister says final safety checks are still being carried out on the Bibby Stockholm.
Image source, PA MediaTransport minister Richard Holden has said he can not put a timeframe on when asylum seekers will be housed on the Bibby Stockholm barge in Dorset.
The Home Office had been planning to send the first 50 migrants to the barge moored at Portland Port on Tuesday.
But final safety checks are still being carried out, with fire service approval pending.
Asked on Sky News when the barge would be available, Mr Holden said: “I can’t put a timeframe on it.”
He added: “The checks are going to take as long as they’re going to take. It’s important we get these things right.”
The barge could become operational on Wednesday, with a Home Office assessment expected later.
The government wants to use barges to house male migrants in an attempt to reduce the bill for hotel rooms.
Senior ministers hope to confirm the use of further barges in the coming months.
They have struggled to find ports prepared to host them so far, with a site next to London City airport and another on the River Mersey in Wirral among those being rejected.
The government believes a successful scheme in Dorset will help encourage other areas to sign up.
But any safety issues would make increasing the use of barges less likely.
The initial plan is for 50 men to live on Bibby Stockholm. But that could increase to more than 500 in the coming months.
The Home Office decided men living on the barge could share rooms, which significantly increased the capacity.
But there has been opposition to the plan – with local councillors and residents staging protests and Conservative MP for South Dorset Richard Drax calling on the government to remove the barge.