Around 20 asylum seekers did not board the barge at Portland today because their transfers were "cancelled" by lawyers, a charity said.

The first arrivals moved on to the Bibby Stockholm barge earlier today.

Pictures appeared to show two men being escorted on to the barge by staff in high-vis jackets, while a coach was also seen arriving at the port.

However, according to refugee charity Care4Calais, around 20 asylum seekers did not board.

Care4Calais chief executive Steve Smith said: "None of the asylum seekers we are supporting have gone to the Bibby Stockholm today as legal representatives have had their transfers cancelled.

"Amongst our clients are people who are disabled, who have survived torture and modern slavery and who have had traumatic experiences at sea. To house any human being in a 'quasi floating prison' like the Bibby Stockholm is inhumane. To try and do so with this group of people is unbelievably cruel. Even just receiving the notices is causing them a great deal of anxiety.

"Human beings should be housed in communities, not barges. The Government could just get on with processing people's asylum claims; instead they are playing to a gallery that seems to thrive on human suffering. We will continue supporting people to challenge their decision."

Steve Valdez-Symonds, Amnesty International UK's refugee and migrant rights director, said: "It seems there's nothing this Government won't do to make people seeking asylum feel unwelcome and unsafe in this country.

"Reminiscent of the prison hulks from the Victorian era, the Bibby Stockholm is an utterly shameful way to house people who've fled terror, conflict and persecution.

"Housing people on a floating barge is likely to be re-traumatising and there should be major concerns about confining each person to living quarters the typical size of a car parking space."

While only a small number of migrants are expected to be housed on the barge at first, Home Office minister Sarah Dine indicated it could increase rapidly to its capacity of around 500 men.

Pressed on whether all of them could be on board by the end of the week, Ms Dines told BBC Radio 4's Today programme: "Yes, quite possibly it will be 500. We are hoping."

But Downing Street appeared to suggest she had misspoken, with Prime Minister Rishi Sunak's official spokesman saying that while "no limit" has been set on how many people will board the barge this week, the Government's plan is to reach the capacity "over time", adding: "I don't think we are aiming to do it by the weekend."

The Home Office later clarified that the total will be reached over a longer period of time and not by the end of the week.

The Government hopes the use of the barge and former military bases to house asylum seekers will reduce the cost of hotel bills.

Ms Dines said those arriving in the country via unauthorised means should have "basic but proper accommodation" and that they "can't expect to stay in a four-star hotel".

The developments came during the Government's "small boats week", in which it is making a series of announcements on the issue that Mr Sunak has promised to solve.