LONDON (AP) — Britain’s Court of Appeal ruled Wednesday that a government policy that gave migrants as little as 72 hours’ notice before they are deported is unlawful.

Under the rule, asylum seekers or migrants whose applications failed were told they had three days to make final representations or be flown out of the U.K. at any time in the following three months. The policy, which was meant to prevent last-minute bids to prevent removals, affected thousands of cases.

Medical Justice, the campaign group that brought the legal challenge, argued that the policy posed a “serious threat to the rule of law” because it would be impossible for many migrants to find a lawyer to represent them at such short notice.

The High Court rejected that claim in September last year, but campaigners took the case to the Court of Appeal. A panel of three judges unanimously ruled Wednesday against the Home Office, saying its policy led to an “unacceptable risk of interference with the right of access to court.”

Rakesh Singh of the Public Law Project, which represented the campaigners, said the policy shut many out of the legal process.

“It meant that when mistakes were made, people could not access the court to put things right, and led the Home Office to remove people with a right to be here,” he said.