Asylum seekers thought to be victims of torture are set to be forcibly removed to Pakistan on the third charter flight to leave the UK in three weeks, The Independent can reveal.

Up to 70 people are set to be sent to Islamabad on Wednesday. Among them are suspected victims of modern slavery, trafficking and torture who have not had the chance to properly fight their case due to poor legal advice, lawyers say.

It comes after a flight deporting 17 Jamaican nationals set off on 11 February. Twenty-five others scheduled to be on board avoided removal after courts ruled that they had not been granted adequate access to legal advice, breaking Home Office policy.

A second charter flight left Britain last Thursday carrying asylum seekers to Germany, Austria and Switzerland under the Dublin convention – which requires people to claim asylum in the first safe EU country they arrive in – despite warnings these individuals may have been denied access to justice.

Those set to be forcibly removed to Pakistan include Mumtaz Ali, 31, who arrived in the UK nine years ago but whose asylum claim has been refused, which he said was in part due to poor legal advice.

Speaking from Colnbrook removal centre, Mr Ali said he arrived in the UK on a visit visa after fleeing his country due to threats of political persecution, which he said led to him being tortured by police.

Mr Ali said that since being issued a removal notice last week, he felt afraid for his life. He said: “I feel depressed. I cannot sleep. I know if I go to Pakistan I will be killed. I’m scared. I haven’t slept in three days.”

He said his solicitor hadn’t responded to his phone calls in days, despite Mr Ali having already paid him to work on his case.

Another man scheduled to be on the flight, who asked not to be named, said he came to the UK as a student in 2010 after being forced to marry his younger cousin in Pakistan when he was just 14, and being tortured after being accused of disobeying his family on a number of occasions.

After completing a masters degree in IT in the UK, he lost his UK status. Fearful of going home, he said he found cash-in-hand work in a takeaway – but ended up in a life of exploitation as the employer refused to pay him and beat him on a number of occasions. The employer threatened to report him to the Home Office if he told anyone about the abuse.

The 35-year-old, who eventually escape the abuse and now has a British wife of eight years, referred himself to the National Referral Mechanism (NRM) – the UK’s framework for identifying victims – last week and was told his case would be considered, but he has not yet heard back.

“It’s depressing and painful leaving family behind. I feel life is ending here. I don’t see any future. They are breaking nine years’ relationship between me, my wife and daughter,” he told The Independent from Harmondsworth removal centre.

Toufique Hossain, director of public law at Duncan Lewis Solicitors, said his team had seen a number of last-minute referrals of victims of modern slavery, trafficking and torture on the flight on Wednesday, adding: “The Home Office know this. They’d rather wait for the courts to intervene than do the right thing.”

Mr Hossain added: “The Home Office continue their relentless practice of mass expulsion by way of charter flights, undeterred even by recent clear examples where removal would have been unlawful.”

Bella Sankey, director of Detention Action, said: “Three attempted charter flights by Boris Johnson’s government in as many weeks – it’s clear this prime minister is no ‘Brexity-Hezza’. He is presiding over a deeply illiberal mass deportation policy, which scoops up victims of modern slavery and long term British residents indiscriminately.

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“Parliament must embrace fundamental reform of this system through the Immigration Bill or knowingly put its trust in a government which boasts contempt for the rule of law.”

The latest charter flight comes after The Independent revealed that a Christian man who was deported to Pakistan last year, despite claims he had been threatened with execution by Islamic extremists there, now says he is living in hiding and in fear for his life.

A Home Office spokesperson said: “The UK only ever returns those who both the Home Office and the courts are satisfied do not need our protection and have no legal basis to remain in the UK.