Haulage firms and lorry drivers have been fined more than £4m after migrants were found in their vehicles – with the number of fines up 50% on last year.
More than 3,300 fines were issued by UK Border Force staff in 2014-15, up from 2,177 in 2013-14, the BBC has learned.
The fines can be as much £2,000 per migrant and can be levied against both drivers and their employers.
Hauliers say the system is “unfair” but the Home Office said many lorries did not have “basic standards of security”.
The fines, known as civil penalties, can be imposed as lorries enter the UK, and also when they are searched by UK officials at ports in France – such as Calais – and Belgium, under the so-called juxtaposed controls system.
The number of penalties issued over the last five years are:
- 2010/11 – 1,497
- 2011/12 – 1,385
- 2012/13 – 998
- 2013/14 – 2,177
- 2014/15 – 3,319 (the appeal period has not concluded, so number could fall)
The figures come amid the crisis around Calais, during which thousands of migrants have tried to board UK-bound lorries.
Lawyers acting for drivers and road haulage companies say the way the fines system is being operated is “unfair” given the dangers their clients face.
Joanne Witheford, a specialist road transport lawyer, told the BBC: “We asked UK Border Force if there was going to be any leniency shown to drivers in the present situation.
“They have told us it is ‘business as usual’, but the situation is anything but usual.
“There are desperate people willing to do anything to get into the UK.”
Ms Witheford said one firm she has been working with had been hit with £36,000 in fines.
She called for immunity for drivers who have taken all reasonable precautions and alerted UK Border Force officials to any suspicions they have.
“Where is the incentive for drivers to inform border staff that they might have clandestine migrants on board?” she added.
Lorry driver Mark Baldwin was fined £600 and his firm was fined £1,200 after he arrived from Calais with migrants in his trailer.
He told BBC Breakfast he had earlier found eight migrants hiding in his lorry at Calais. They were removed after he alerted French authorities.
When he arrived in the UK he asked border staff to check his lorry again and they discovered three more stowaways, he said.
His fine has been rescinded, but he said his firm – which has since stopped making trips to the continent – had to pay its penalty.
“It is like going to a policeman and saying ‘I have seen this crime’ and then getting fined for telling them,” he said.
Simon Clarke, head of transport law at Cartwright King Solicitors, said a system must be in place to protect drivers, and there should be “incentives rather than penalties” for those who are targeted.
He told BBC Radio 4’s Today programme that checking large lorries was often difficult and time-consuming.
The Home Office said only 7% of penalties imposed were issued to British drivers.
“Most hauliers take their responsibility for vehicle security seriously but, despite co-operation from the British haulage industry, Border Force estimates one third of lorries arriving at the UK border do not have basic standards of security,” a spokesman said.
“Drivers who can show they have taken simple steps to secure their vehicles will not receive a penalty.”
Haulage firms have mounted a legal challenge and, early next year, the Court of Appeal will look at whether the penalties are being “fairly applied”.