It’s a cold night and we’re standing with our backs to the diagonal rain, hands plunged deep in pockets. We’re in the car park of a museum of war relics and memorabilia, on a disused airfield just outside Ramsgate, Kent. Across the road is the Manston ‘short-term holding facility’ for asylum seekers.

It’s 7pm and the security shift has just changed. Omar* has finished a 12-hour shift, one of six he’ll do this week. He usually lives in Birmingham, but has had to relocate to be nearer to work. He’ll be back again at 7am.

Last week, Omar was one of 400 security staff on shift. Now, there are only 50. Workers come from as far away as Glasgow, Coventry and Bristol. Home Office-contracted security agencies on site attract employees with promises of long hours. But zero-hour contracts mean shifts can be cut at a day’s notice: 80 hours of work one week can be followed by none the next.

In late November, the Home Office came under increasing pressure over the conditions at Manston, with reports emerging of daily protests by detainees. The people being held at the centre were rapidly relocated across the country – to hotels, temporary accommodation or, sometimes, just to coach stations. Security became an unwanted expense. Shifts were cancelled overnight.

A week later, when the weather over the Channel improved, migrant crossings from France resumed and detainees appeared at Manston again. Security staff were called back to work. Edvin* was one of them. Originally from Albania, he had driven nearly 200 miles from Bristol with his guard dog. He spoke to us while kneeling over a simmering broth in the back of his van.

“Last night was my first shift. I had one hour of sleep after my last job, before they sent me here. Today I tried to sleep, but [the security agency] called me into work the day after a night shift.” The absurdity of this kind of employment is not lost on Edvin, but he has children to look after.

“I’ll work every night for the next month, then hopefully I’ll get a week off to go see my family.”

Dozens of Edvin’s colleagues also sleep in the back of vans outside the detention centre. They are predominantly from east Africa, west and south Asia and Albania – the same regions that most of the detained asylum seekers came from.

A Home Office spokesperson told openDemocracy it could not comment on the arrangements between its contractors and their staff, but said that fluctuations in the number of people being held at Manston mean “flexibility around when to use staff is an important way to ensure value for money for taxpayers”.

Outsourcing the UK border regime

Shift workers like Omar and Edvin are at the bottom of the many layers that sustain the UK’s border regime. The Home Office relies on thousands of private contracts for its immigration detention operations – from marquee construction to catering, coach hire and proto-police.

This is outsourcing meeting the hostile environment. For these security guards, it means low pay for 12-hour shifts in freezing-cold car parks. Some locals have also made both security guards and detainees feel unwelcome. When we were in the car park, the manager of the museum mistook us for security staff waiting for lifts home and threatened to call the police.

Staff we spoke with at Manston claimed that as you move up the pay scale, the workforce becomes whiter and is responsible for interacting with detainees – those on lower salaries say they are forbidden from doing so.

A spokesperson from the Home Office denied this, telling openDemocracy that the department is an equal opportunities employer.

They added: “We work with a number of contractors to ensure Manston is appropriately staffed to meet any and all possible requirements related to the reception and processing of migrant arrivals via small boats.

“The Home Office ensures all its contractors employ people in accordance with their wider legal obligations under employment and equalities law.”

The most securely employed at Manston are Border Force staff, who are part of the Home Office and have civil service contracts and reliable hours. But they are also facing the government squeeze on public sector pay, and last month those represented by the PCS union voted to take strike action over pay and conditions.

Enduring border violence

Across the UK, Black and Brown workers are often the first to be outsourced, casualised or pushed into informal and unprotected arrangements. Security, delivery, cleaning, construction and hospitality are some of the industries where workers endure border violence.

In May, for example, the Metropolitan Police raided Ashwin Street in Dalston, north London, with onlookers reporting that officers targeted the delivery app riders who congregate there while waiting for orders. The police force disputed this, claiming to have been “targeting e-scooters and moped-enabled crime”.

While checking riders’ vehicle insurance, Met officers also reportedly inspected some people’s immigration status, and several couriers were arrested for immigration violations. The situation escalated, but a quickly mobilised crowd prevented the riders from being taken to the police station.

It has been suggested by the Independent Workers’ Union of Great Britain that similar immigration raids in Hackney this year could have been in retaliation to protests by delivery riders demanding safe waiting spaces.

Border enforcement within precarious industries is not a recent phenomenon. In June 2009, management at London’s School of Oriental and African Studies (SOAS) called an emergency staff meeting for outsourced cleaning staff, where they were met by 40 immigration officials. Nine of the cleaners were detained and at least six were deported.

At sites like Manston, the struggle against the Tories’ harsh immigration policy comes into sharp focus via the lens of the wave of union organising that has been gathering momentum this summer.

But this wave has so far failed to challenge nationalist narratives that endorse locking up and deporting detained or unorganised workers, or those with precarious visa statuses.

Trade unions must recognise that border violence is union business. To remain credible, the labour movement must organise among the most precarious of workers, who occupy the nexus of a xenophobic border regime and the neoliberal trend to an outsourced labour market.

We have two options. Embrace class struggle and unity between those who are detained, outsourced and underpaid. Or, fall back into nationalist campaigns, demanding more money for pushing back migrants, which entrench detention, division and exploitation of working people. Which will we choose?

• The employees mentioned in this piece have been created from the testimonies of multiple people openDemocracy spoke with at Manston, to protect their identities.