The women and equalities committee said the risk of harm to asylum-seeking children outweighs that of damaging the government’s goal of deterrence through its Illegal Migration Bill.
Under the planned Bill, people who enter the UK illegally through a safe country would be detained and removed, to their home country or a safe third country such as Rwanda.
But the committee’s chairwoman, Conservative MP Caroline Nokes, said one of the biggest concerns was the treatment of children in the asylum system.
Ms Nokes urged the government to abandon any intention of detaining and forcibly removing minors.
The critical report is the latest in mounting pressure on the government to change its approach to the treatment of asylum seekers, especially children.
It comes a week after a coalition of leading medical organisations warned that child migrants detained under the new laws could be at risk of post-traumatic stress disorder, clinical depression and suicidal behaviour.
Before the Bill’s return to the House of Lords on Wednesday, schoolchildren were due to gather outside Parliament, writing messages of support on giant teddy bears in a protest organised by Citizens UK and Together With Refugees.
The committee’s report on equality and the UK asylum process concluded that people with particular vulnerabilities could see the risk of harm rise under recent and proposed changes to the Home Office’s management of the asylum process.
“People with vulnerabilities arising from Equality Act-protected characteristics, including women with histories of gender-based violence and abuse, children, lesbian, gay, bisexual and transgender people, and disabled people, experience unnecessary risks under the Home Office’s management of the asylum process,” it said.
“Recent and proposed changes to the system are likely to increase those risks. The Home Office must demonstrate it is taking effective steps to mitigate unequal effects.”
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The MPs said it was “unacceptable that the Home Office remains unable to set out a clear plan to monitor and mitigate” those unequal effects.
They demanded an updated equality impact assessment be published within three months in relation to the Nationality and Borders Act’s asylum provisions.
The committee said prolonged detention of people who posed no threat to the public and for whom there was little prospect of removal from the UK was “potentially harmful, impractical and costly”.
They warned of MPs’ deep concerns that planned reforms “risk turning back the clock on policies intended to ensure detention is used only as a last resort, and to reduce the risks of harm to vulnerable people”.
The MPs recommended the government set out its planned approach to easing risks of harm to vulnerable adults in detention, abandon any intention to detain and deport children, and collect and publish data on the protected characteristics of detained asylum seekers, including where they are detained and for how long.
They said that a “significant number of vulnerable people, to whom the removal process would very likely be harmful” have received notices of the Home Office’s intention to remove them to Rwanda.
The MPs called for such notices to be suspended, with no new ones issued “until all legal challenges to the policy are complete”.
The wide-ranging report also called on the Home Office to “stop the dangerous practice of moving pregnant women and new mothers between asylum accommodation settings”, saying the department is “too often failing to comply with guidance” on this issue.
It said an urgent review of protection was needed, describing plans to accommodate asylum seekers in barges as “unacceptable from both safeguarding and equalities perspectives”.
“There must be an urgent review of safeguarding, including steps to prevent LGBT hate crime and violence against women, across all types of asylum accommodation, including the newly acquired accommodation barges,” the report stated.
Ms Nokes said: “We were disturbed by the Home Office’s inadequate management of risks of harm to asylum seekers with protected characteristics, including women, LGBT people, children and disabled people.
“Alarmingly, these risks will increase under the government’s recent and planned reforms.
“One of our biggest concerns is the treatment of children within the asylum system.
“Any intention to detain child asylum seekers under the Illegal Migration Bill and forcibly remove them to Rwanda must be abandoned.
"The risk of harm to children outweighs any perceived damage to the effectiveness of the government’s policy agenda.”
A Home Office representative said: “Through the Illegal Migration Bill, we will stop the boats by detaining those who come to the UK illegally and swiftly returning them to a safe third country or their home country.
“It is only right that we protect the most vulnerable by not creating incentives for criminal gangs to target specific groups.
“We have amended the Bill to make clear that an unaccompanied child under 18 can only be removed in very limited circumstances.
“Where a removal decision is made, detention will be for the shortest possible time with necessary support provisions in place.”
Meanwhile, government documents released on Monday showed that sending a migrant from the UK to Rwanda or another third country would cost nearly £170,000 ($216,000).
“This cost will only be incurred for people who arrive in the UK illegally. If an individual is deterred from entering the UK illegally, then no cost would be incurred,” showed an economic assessment of the Illegal Migration Bill, published on Monday.
The document also suggests the “costs savings of relocating individuals to safe third countries” is “highly uncertain” but gives figures of between £106,000 and £165,000 a person.
Home Secretary Suella Braverman said the assessment proved that “doing nothing is not an option”.
“We cannot allow a system to continue which incentivises people to risk their lives and pay people smugglers to come to this country illegally, while placing an unacceptable strain on the UK taxpayer,” Ms Braverman said.
“I urge MPs and peers to back the bill to stop the boats, so we can crack down on people-smuggling gangs while bringing our asylum system back into balance.”
Her plan to house asylum seekers on barges was described as “unworkable” as she missed her own target for the first vessel to be in place.
The Bibby Stockholm accommodation vessel, which will house about 500 people, has not yet arrived at Portland, Dorset, despite Ms Braverman promising MPs it would be in the dock a week ago.
The barge is in Falmouth, Cornwall, for checks, maintenance and refurbishment.
On June 5, the Ms Braverman told the Commons: “We will see an accommodation barge arrive in Portland within the next fortnight."
Liberal Democrat home affairs spokesman Alistair Carmichael said: “This seems to be another case of Home Office policy by press release that is failing to materialise.
“Braverman’s plan for a barge on the Dorset coast is an unworkable plan that is wasting time and money, much like all of this government’s asylum policy.
“The Home Secretary needs to get her priorities straight.
“She should focus instead on tackling the backlog of asylum cases created by her government’s sheer incompetence, which has created the need for this plan in the first place.”
Ms Braverman wants to use barges and sites including converted military bases to house asylum seekers and reduce the £6 million daily cost of hotel accommodation while people await a decision on their status.
The Bibby Stockholm was the first barge secured under the plan, but its journey to Portland will now take place in the coming weeks, the Home Office said.