Hundreds of Syrian asylum seekers are struggling to survive in the UK, with some facing destitution and others forced into exploitative work because they are afraid of being detained and deported.

The Observer has found Syrian asylum seekers working in warehouses, construction sites and garages for as little as £10 a day. Many had stopped signing in with the Home Office after being held in detention centres for months. Hundreds more are living in destitution, reliant on charities for food parcels and clothes.

Mike Adamson, chief executive of the British Red Cross, said: “A two-tier system, where Syrian nationals who arrive in the UK as asylum seekers are left vulnerable to exploitation, seems completely at odds with the spirit behind the government’s commitment to offer a safe home to 20,000 Syrian refugees under its resettlement programme.

“No one should arrive in the UK having fled conflict or persecution only to be left destitute and reliant on charity to survive.”

The Observer interviewed 10 Syrians, all living in limbo because of the Dublin regulation, which means asylum seekers can be sent back to the first EU country they reach. The men were fighting removal to countries including Bulgaria, where Human Rights Watch found asylum seekers being shot at, beaten with weapons by uniformed officials and sent back to Turkey. Several of the men we spoke to were being threatened with removal to Hungary, despite the fact that the Home Office told the Observer that it is not currently returning asylum seekers there.

At least 50 Syrians have been removed under the regulation since the start of 2015, prompting some to drop off the radar. Eight of the men interviewed said that they had stopped signing in with immigration authorities because they were afraid of detention and removal. Most had family in the UK and were supporting themselves by working illegally.

Tarek, 31, has been living in the UK without documents for nearly four years. He stopped signing in with the Home Office after he was held in a detention centre for three months. “After that, I was too scared to go and sign in,” he said.

Desperate for work, he found a job working with a mechanic at a garage. “Every day I’d get £10 and food and you could sleep in the garage. I worked there for three months,” he said. He is being threatened with removal to Bulgaria.

Sayid, 25, arrived two years ago. After being held in a detention centre twice, he found a job in a warehouse on the outskirts of London. “I was moving food crates, carrying boxes from a lorry to a van. I’d work for 10 hours,” he said. At first he was paid £3.50 an hour, then that rose to £50 a day. “I only got enough money to survive. I’m so up and down in my mind and my body, I’m not happy. In this job there are no human rights, but what can I do? I can’t do anything.”

The investigation also found Syrians working as gardeners, tiling bathrooms and in restaurants. Those not working and still reporting to immigration said they could not survive on the £36 a week they receive in benefits.

Osama, 18, arrived last October. He was severely wounded by shrapnel when his house was destroyed in 2015. He has been waiting for four months without papers, meaning he is reliant on government handouts. “It is so bad waiting,” he said, “I just wake up, eat, maybe see friends, then I do nothing. I would work if I was allowed.”

The Red Cross said it had seen 1,341 destitute Syrian asylum seekers in Britain last year, up from 1,159 the year before. In South Yorkshire, a quarter of all destitute asylum seekers seen, of all nationalities, said they experienced hunger every day. In nearly half of all the cases seen by the Red Cross, asylum seekers were facing destitution, despite receiving the full £36 a week afforded to them under government rules. The Syrians the Observer interviewed said they were often too scared to pick up their allowance for fear of being detained.

Migrant Voice, an NGO, has produced a study based on the testimony of 11 people in limbo because of the Dublin regulation. Nazek Ramadan, Migrant Voice’s director, said: “The Dublin regulation gambles with the lives of vulnerable people fleeing the world’s most desperate circumstances, treating refugees like balls to be bounced from country to country with no chance of building a real future.”

A Home Office spokesman said: “The UK has a proud history of providing protection to those who need it. But it is also right that we uphold the principle that those seeking asylum should ask for protection in the first safe country they reach. Where there is evidence someone has claimed asylum in another European country, we will seek to return them there.”

Some names have been changed