Lorries using three service areas on West Midlands motorways were checked for stowaways in a crackdown on illegal immigrants entering the UK.

The UK Border Agency sent officials to the Warwick Services on the M40, Corley on the M6 and Hopwood Park on the M42. They scanned vehicles with probes which detect human breathing inside.

Simon Excell, deputy regional director for the agency, said: “The message is that the UK is not a soft touch.

“It is not easy for illegal immigrants anywhere in this country. We will take action: we will arrest, detain, and return you to your country of origin.”

Although yesterday’s search failed to find any stowaways, the agency believes their programme is working.

“It is unusually quiet for this time of year,” said Mr Excell.

“We’ve conducted 20 raids throughout the Midlands and Eastern England over the past few weeks, and have been surprised that the number of illegal immigrants trying to hide in lorries has dropped substantially. It does seem that word is getting round.”

The Border Agency claims they have the support of most lorry drivers, many of whom Mr Excell said are “victims themselves”.

“We only punish drivers if they have not made sufficient checks,” he said.

The agency has stopped 18,500 immigrants trying to make their way into the UK illegally at the Channel ports this year, and searched 750,000 vehicles.

Earlier this week the government began its introduction of compulsory ID cards for all foreign nationals, in an attempt to help businesses who employ foreign workers crack down on illegal working.