Hiring migrants illegally will be “financially ruinous” for businesses under a new crackdown to stop Britain from being seen as soft on immigration.

Fines for bosses who employ migrants in the UK illegally will triple to up to £60,000 per employee, making the practice so economically damaging that it can “put them out of business”.

The move, announced on Sunday by Robert Jenrick, the Immigration Minister, aims to end the perception of the UK as a soft touch for Channel migrants who believe they can easily find work in Britain’s black market.

Landlords will also face a ten-fold increase in fines if they let properties to migrants or take them on as lodgers without checking their immigration papers.

Ministers believe the move will help “stop the boats”, one of Rishi Sunak’s five key pledges.

It comes as the Home Office is on Monday expected to move the first asylum seekers to the Bibby Stockholm barge in Dorset from their taxpayer-funded hotels.

A source said the aim of the crackdown was to make it “completely economically unacceptable and financially ruinous” to risk employing workers illegally. “It is essentially putting people out of business if they do it,” said the source.