British social care agencies have been accused of exploiting foreign workers, leaving people living on the breadline as they struggle to pay off debts run up while trying to secure jobs that fail to materialise.

Dozens of people working for 11 different care providers have told the Guardian they paid thousands of pounds to agents to secure jobs working in UK care homes or residential care, with most finding limited or no employment when they arrived.

Many are now struggling to pay off huge debts in their home countries and having to work in irregular jobs for below the minimum wage.

Labour and the Conservatives are now under pressure to tackle the issue if they win next month’s election. The Tories recently banned foreign care workers bringing their dependents to the UK with them, a ban Labour said last week it would keep in place in an effort to bring net immigration down.

But experts say the ban has failed to tackle the deeper issue of exploitation of the workers themselves, many of whom are still in the UK and living in poverty, afraid to leave their employers for fear of losing their visa status.

The Royal College of Nursing (RCN) has now written to the leaders of all three major national parties to demand a full government inquiry into treatment of migrant care workers when parliament returns.

Prof Nicola Ranger, the acting general secretary of the RCN, said: “The exploitation of migrant care workers is a national scandal but little has been done to tackle it.

“A chronically understaffed social care sector has supercharged its recruitment of staff from overseas and a lack of regulation and enforcement has allowed some employers to profit from the mistreatment of migrants.”

She added: “An urgent government investigation into exploitation across the social care sector must be a priority for whoever wins the general election. Lives are being ruined daily and this work has to start as soon as possible.”

David Neal, who raised the alarm about the care visa system when he was the government’s borders inspector, said: “As soon as we looked at social care visas, we realised there was exploitation going on.”

He added: “Throughout my inspection, I was thinking of the Windrush scandal and there are echoes of it here: the state inviting workers to come to this country to help us in the labour market and then abandoning them.”

Lawyers say UK care providers who promise regular full-time work and then offer exploitative or underpaid jobs on arrival may have broken the law. The sponsorship system means an individual’s visa status is tied to a particular employer, meaning many feel trapped.

Johanna White, a solicitor at the Anti-Trafficking and Labour Exploitation Unit, a charity, said: “I can see what look like indicators of trafficking and modern slavery.

“In many cases, there appears to have been deceptive recruitment, with the individuals being given false information and promises to induce them to pay large fees upfront to the agents for the opportunity to live and work in the UK, being left vulnerable to forced labour, financial exploitation or both.”

The care industry has turned to foreign workers in their hundreds of thousands in recent years to solve labour shortages caused by Brexit and the Covid pandemic. The government granted 350,000 health and care visas in 2023 to workers and their dependants, accounting for 75% of all skilled worker visas issued.

But as the numbers have risen, abuse of the system appears to have done so too.

The Guardian spoke to more than 30 workers, all of whom came from India – though they said others from sub-Saharan Africa had suffered similar experiences.

All shared roughly the same story, of paying immigration agents – and in some cases, the care provider itself – several thousand pounds in fees to secure a visa to work either in a care home or as a carer in people’s homes.

Most said the agents promised them the money would cover the visa, flights and a month’s accommodation, and that they would be guaranteed full-time work earning above £20,000 a year. The salary would quickly clear any debt incurred to pay the initial fees, many say they were told.

Shortly before arriving in the UK, however, workers claim they were told they would have to pay for their own flights and find accommodation for themselves. And then when they arrived, they did not get the jobs they were promised. In most cases there was no work at all or the hours and pay were far less than promised.

Some workers said their employers encouraged them to find casual work elsewhere, as allowed under the terms of their visa.

Workers at one company said they were pressed to work for that company as drivers or cleaners instead. Several said they have been using food banks, while some said they were sharing rooms, and even beds, with other immigrants to make ends meet.

In several cases, workers complaining about the conditions say they were told their sponsorship would be removed if they did not remain silent and they would be deported back to India. Some said their families had also been threatened by Indian-based immigration agents should they try to speak out.

Shahid Chera Pparambil, one of the workers, said: “If I go back to India, I don’t have anywhere to live. I don’t have any option other than committing suicide.”

He added that the debt he had incurred in India was now causing problems for the family he had left behind: “People are coming and demanding money from us, from my wife and family. I can’t bring them here, there is no living. I am totally locked.”

Neal’s report, which was published after he had been sacked from his role, warned that the Home Office did not have sufficient oversight of the visas being offered.

He found hundreds of certificates of sponsorship – documents needed to secure a skilled worker visa – being granted to one company that was pretending to be a care home and thousands to a company without its knowledge. For every 1,600 employers licensed to sponsor foreign workers, there was only a single inspector.

A Home Office spokesperson said: “We prevent overseas care workers from entering the United Kingdom without genuine roles or fair pay to safeguard against destitution.

“Illegal labour market activities face zero tolerance; we enforce strict measures against exploitative care providers. The number of visas granted has been reduced as we tackle noncompliance and abuse head-on.”

Six of the 11 employers identified by the Guardian have had their licences to bring in more foreign care workers suspended or cancelled. However, the other five retain the ability to bring in workers from abroad.

Almost all of the care workers who spoke to the Guardian were still in the UK. While some have found employment from new sponsors, many are having to work irregular shifts as cleaners or drivers, often being paid below the minimum wage, to make a living.

Neal said the entire system of allowing companies to issue certificates of sponsorship – a system usually used for high-end professional jobs – was inappropriate for the care industry, where exploitation is common.

“Anyone in this area knew this was the wrong way to get more people into the social care sector,” he said.