Using barges such as the Bibby Stockholm could be “catastrophic” for the mental health of those seeking asylum, a therapist has warned.

Ann Salter, who works for the charity Freedom From Torture, said making people live on water after experiencing potentially traumatic events while making dangerous journeys on small boats could impact their wellbeing.

She has previously called the plans to house asylum seekers on barges a “mental and physical health catastrophe waiting to happen”.

Her warning comes as the Bibby Stockholm barge arrives in Portland, Dorset, where it will house 500 asylum seekers.

The trauma of being on water and having to cross water, to get on to dry land, and to be on a barge on water is not good

In an interview with the PA news agency, Ms Salter said: “I know people’s experiences from the hotels have been catastrophic for people’s mental health, the barges are going to be much worse.”

The clinical services manager for the north west said that those who have fled to the UK will “most certainly” have experienced trauma from their home country or journey, and that conditions such as living in a “prison camp” on the sea could re-trigger this.

Ms Salter said: “What we know from experience from our clients, [they have] experienced seeing other people drowning, experienced family members drowning, tried to save lives of others.

“That awful thing trying to hold onto somebody and losing that person, not being able to hold on.

“The trauma of being on water and having to cross water, to get on to dry land, and to be on a barge on water is not good.”

Overall, Ms Salter said the barge policy was “disastrous”, adding: “It’s really not acceptable, full stop.”

The Manchester-based therapist explained the way clients often manage their symptoms such as flashbacks is to go for a walk, be in the open air and greenery, which she fears they will have “limited access” to by living on a barge.

Ms Salter also flagged concerns over the barges being targeted.

She said: “We know hotels have been targeted by far-right groups, when that happens it’s really frightening and the fear of that as well.

“I do worry about barges being targeted [because] they are so visible.”

The Government has said it has to use alternative accommodation due to numbers of people seeking refuge in the UK but Ms Salter said the problem stems from the backlog in processing asylum cases.

She said: “We have never seen such delays, the delay in people’s asylum claim being assessed has a huge impact on people’s mental health.”

Regarding physical health, Ms Salter highlighted issues seen in hotels where people are unable to cook their own food, which can cause “real problems” for people who need to follow particular diets for health reasons.

A Home Office spokesperson said barges offer “better value” for taxpayers than using hotels to home asylum seekers and have been used by other European countries without leading to “the alleged problems” on mental health.

They added: “All asylum seekers are screened to protect vulnerable individuals and ensure they are placed in suitable accommodation.

“They have access to health and social care services, including support for mental health, from point of arrival in the UK and will continue to while housed on the Bibby Stockholm.”