A mobile clinic operated by Doctors of the World UK (Medecins du Monde) is operating outside a former air base housing asylum seekers
A mobile clinic operated by Doctors of the World UK (Medecins du Monde) is operating outside a former air base housing asylum seekers AFP

Outside an isolated former military base in the English countryside, a small medical team pitches up to assess and aid growing numbers of asylum seekers held there.

The converted Royal Air Force base, northeast of London, is part of contentious efforts by the UK government to shift thousands of asylum seekers from costly hotels into other accommodation.

But critics say such places are ill suited to host vulnerable people who in many cases have been through traumatic experiences.

"It's very hard inside," a visibly weakened Eritrean man in his 20s said in broken English as he arrived for an appointment with the medics at the razor-wired edge of the base this week.

The team from France's Medecins du Monde (Doctors of the World) charity has been operating the mobile clinic outside the Wethersfield barracks three days a week since early December, in partnership with fellow NGO Doctors Without Borders (MSF).

Consisting of a doctor and an assistant, and often including Medecins du Monde's UK director Simon Tyler, they can offer only limited care from the van loaded with basic medical equipment and supplies.

Patients come in for a variety of ailments, in particular intestinal pain, he said.

"But clearly the number one morbidity is mental health and psychological issues -- it's the number one by a mile," he said.

For Tyler, the base is exacerbating those problems and heightening the risk of suicides inside.

"It's clearly inappropriate, especially considering the vulnerability of the people here," he said of the site, which is several kilometres from the nearest village and almost half an hour's drive from the closest town.

"It feels like a detention centre. They can leave, but they have absolutely nowhere to go. They feel desperate, and staying here exacerbates this.

"Some are showing suicidal tendencies," Tyler added.

With a general election looming later this year and immigration a top concern among many voters, the Conservative government is trying to reduce the numbers arriving by regular and irregular methods.

Around 30,000 people crossed the Channel on small boats in last yer, down by around a third on the nearly 46,000 the year before.

But it is still seen as a potent symbol of the Tories' perceived failure to control UK borders after its Brexit departure from the European Union.

Once in the UK, many eventually gain asylum -- around two-thirds of applications were approved last year -- but that often requires years of waiting.

Prime Minister Rishi Sunak wants to ease the backlog and deter more cross-Channel arrivals by transferring a small proportion permanently to Rwanda.

The policy remains stalled amid legal challenges, however.

Meanwhile, officials have been moving those awaiting a decision from hotels to bases like Wethersfield and other sites to drive down costs.

Several hundred are being housed on a barge docked in southern England, which some have likened to a prison and where one asylum was found dead in a suspected suicide in December.

The first migrants arrived at Wethersfield, which can house up to 1,700 people, in July and its population has steadily risen to around 700, according to the interior ministry.

Entry to the site, which is in interior minister James Cleverly's parliamentary constituency, is strictly monitored.

All the residents are male and over the age of 18. Most hail from Afghanistan, Syria, Iraq and Eritrea.

Crossing the Channel was the last stage of long, perilous journeys.

But when the men talk to the Medecins du Monde team, "you don't hear stories about the horrific journey they have taken, you hear stories about this place," Tyler told AFP.

"Their biggest concern is being confined in a location like this, remote, feeling like somehow (they are) in prison."

He said the migrants recount fights occurring inside the barracks and difficulties sleeping.

"Some vulnerable individuals are constantly feeling unsafe in this environment," he said.

The team sees around 25 people each week, with some pre-booking appointment slots while others just try their luck by knocking on the door.

Very few speak English, which complicates consultations with the NGO. It uses a telephone translation service to get around the language barrier.

Appointments can last up to an hour so that patients have ample time to discuss matters.

"They are more comfortable with us," Tyler said. "There's a high level of trust. They know what they say to us is not going to have an impact on their migration status."

Doctors are concerned about psychological trauma of migrants held at the base in eastern England
Doctors are concerned about psychological trauma of migrants held at the base in eastern England AFP
Medics liken the Wethersfield barracks to a detention centre
Medics liken the Wethersfield barracks to a detention centre AFP
Medecins du Monde UK director Simon Tyler says his group can offer only limited care with no access to the base
Medecins du Monde UK director Simon Tyler says his group can offer only limited care with no access to the base AFP
Migrants have been moved to decommissioned military bases to cut costs of housing people in hotels
Migrants have been moved to decommissioned military bases to cut costs of housing people in hotels AFP