A federal judge has struck down a policy aimed at helping undocumented spouses of US citizens obtain legal status, dealing a blow to outgoing President Joe Biden and an estimated half a million people eligible under the programme.

According to AFP, the ruling comes just days after Donald Trump swept to victory in the presidential election on promises of cracking down on illegal immigration and launching a massive deportation effort.

The “Keeping Families Together” policy, which had been previously suspended amid a court challenge, allowed certain undocumented immigrants married to US nationals to apply for permanent residency without leaving the country, as was previously required.

Judge J. Campbell Barker, of the Eastern District of Texas, who was nominated by Trump during his first White House term, ruled that federal agencies “lack statutory authority” for the programme.