The United Kingdom arrested hundreds of people in a clampdown on migrants working illegally as drivers for delivery firms, as part of Prime Minister Keir Starmer’s push to stem the flow of irregular immigration.

The July 20-27 operation by immigration enforcement teams led to 280 arrests being made for illegal working, the Home Office said on Saturday in an emailed statement. And as a result of that, some 53 people are having their asylum support reviewed, which could result in the assistance being suspended or withdrawn, it said.

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The effort to tackle illegal work for delivery firms follows a Sun newspaper report last month that some asylum seekers living in taxpayer-funded hotels were illicitly earning extra money by working for the likes of Deliveroo Plc and Just Eat Takeaway.com NV as delivery riders.

Generally, asylum seekers are not allowed to work in the UK while their claim is being assessed.

“Illegal working undermines our border security and we’re cracking down hard on it,” Home Office Minister Angela Eagle said in the statement.

“We have intensified our enforcement activity right across the UK to crack down on those who think they can evade immigration and employment laws.”

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The government last month reached an agreement with delivery firms to ensure they receive new information regarding the location of asylum hotels to help them identify those seeking to work illegally.