The Windrush scandal has exposed one of the "cruellest examples of unaccountable state power targeting the vulnerable", MPs heard, as ministers faced fresh calls to provide legal aid to victims.
Shadow justice secretary Richard Burgon took to the despatch box to demand free legal advice be offered as he branded current immigration law "complex and unintelligible".
Justice Secretary David Gauke, speaking in the Commons, refused to commit to fund legal advice for those affected - instead telling MPs that a compensation scheme had been set up which would go to "those who deserve it".
The demands follow revelations that long-term residents who settled in the UK from the late 1940s to early 1970s had wrongly been identified as illegal immigrants.
People who had arrived in the UK before 1973 were automatically granted indefinite leave to remain but the Home Office did not keep a record of those allowed to stay or any documentation confirming their status.
While many of those who arrived have taken British citizenship or have official documents proving their status, others have struggled to source paperwork demonstrating they are lawfully resident.
Mr Burgon, speaking during justice questions, said: "The Windrush scandal is one of the cruellest examples of unaccountable state power targeting the vulnerable, the defenceless and the innocent that I can ever remember."
He added: "I was disappointed yesterday to hear the Home Secretary say that people affected by the Windrush scandal will have no need for lawyers. I'm sure the Justice Secretary will understand why the words the Home Secretary used won't do.
"So, will the Justice Secretary guarantee today that all those put in this kind of situation will have access to the necessary legal advice to help them when they most need it?"
Mr Gauke responded: "The Home Secretary set out a comprehensive plan yesterday about how we will make this process much easier for those who have been affected by this issue.
"They are going to be able to obtain British citizenship for example much more easily, those who have retired back to another country are able to come here without great difficulties with visas, and so on.
"The Home Secretary has also set out how we're going put in place a compensation arrangement to ensure that there is compensation for those who deserve it."
On Monday, Home Secretary Amber Rudd announced an emergency package of measures designed to resolve the crisis.
Under the plans, thousands of people who arrived from the Commonwealth will be offered the chance to obtain British citizenship free of charge and without the requirement to take language tests.
A major exercise has also been launched the check no-one has been wrongly deported, and the Home Office is preparing a compensation scheme for those affected by the failings.