An appeal hearing into whether two High Court judges were right to dismiss legal bids against ministers’ plans to send asylum seekers to Rwanda is due to start on Monday.
A group of individuals from countries including Iran, Iraq and Syria are aiming to overturn rulings made in December.
Last year, Lord Justice Lewis and Mr Justice Swift dismissed a series of legal bids against the Government’s plan to send asylum seekers to Rwanda.
But the pair gave the go-ahead to several individual asylum seekers and the charity Asylum Aid to appeal against their decision.
In a hearing due to last four days, the Court of Appeal will be asked to consider whether the two judges were wrong to find there were sufficient safeguards to prevent asylum seekers from being returned to a country where they were at risk of persecution and whether the Rwanda scheme is “systemically unfair”.
Chief executive Sonya Sceats said: “This case cuts to the heart of the UK’s role as a place of safety for survivors of torture and persecution from countries like Afghanistan and Iran who have been denied safe routes to reach our shores.
“We know from our clinical services that survivors of torture struggle to disclose their traumatic experiences, even in a safe therapeutic environment.
“In this exceptionally hostile and fast-paced scheme, there is a grave risk that they will not be identified and will be expelled from the UK.”
She added: “No matter what the courts decide, this scheme and the ‘Refugee Ban Bill’ are unacceptable and contrary to the compassion we should be showing to people who need our help.”
The Rwanda deportation plan, along with the Illegal Migration Bill — which is due to return to the Commons on Wednesday — is part of Prime Minister Rishi Sunak’s pledge to stop migrants crossing the English Channel in small boats.
The approach has been denounced by the UN’s refugee agency as an effective “asylum ban”.
Several challenges were previously brought against the proposals, which were described at the time as a “world-first agreement” in a bid to deter migrants from crossing the Channel.
The first deportation flight – due to take off on June 14 – was grounded amid a series of objections against individual removals and the policy as a whole.
Following hearings in September and October, Lord Justice Lewis and Mr Justice Swift rejected arguments that the plans were unlawful.
However, they ruled in favour of eight asylum seekers, finding the Government had acted wrongly in their individual cases.
Separately, two charities are warning that the Illegal Migration Bill could lock up thousands of refugee children who have become separated from their parents.
According to an impact assessment by the Refugee Council, it estimates that about 15,000 unaccompanied children would have their asylum claims deemed inadmissible in the first three years of the implementation of the legislation.
As a result, the Refugee Council and children’s charity Barnardo’s said those children could be detained or face deportation to the country they have fled or a third country, such as Rwanda.
They could also be banned from remaining in the UK as refugees when they turn 18, the two groups said.
The charities are calling on MPs to support amendments to exclude children from the legislation.
Barnardo’s chief executive Lynn Perry said: “In its current form, this Bill has serious implications for the safety and protection of children.
“As a charity that has a long history of supporting children who need us the most, Barnardo’s is deeply concerned that this Bill will prevent children seeking sanctuary in the UK, who have suffered trauma, exploitation and trafficking, from getting the critical help and support they so urgently need.”