Haulage firms and lorry drivers owe more than £4m in fines imposed by UK Border Force staff after migrants were found on their vehicles.
The BBC has learned that more than 3,300 fines were issued in 2014/15 – an increase of more than 50% on 2013/14.
The fines can be as much £2,000 per migrant and can be levied against both the driver and their employer.
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 ahead of their arrival in the UK, 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 escalating crisis around Calais, during which thousands of migrants have tried to board UK-bound lorries, some of which have faced delays because of strikes on the French side of the Channel Tunnel.
On Monday night alone, migrants are said to have made 600 attempts to enter the tunnel to try to stow away on lorries.
Richard Jameson, who runs a transport company based in Marlow, Buckinghamshire, said lorry drivers were facing an increasingly dangerous situation at Calais.
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.
“They have tools to break locks and knives to cut curtain-sided vehicles. It’s just not safe for drivers to get out of their cabs to prevent this.”
Ms Witheford said one firm she has been working with had been hit with £36,000 in fines.
She is calling 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 said.
The Home Office points out that only 7% of penalties imposed are issued to British drivers.
A Home Office spokesman said: “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.
“The purpose of the civil penalty regime is to ensure that all drivers are taking reasonable steps to stop migrants from boarding their lorries.
“Drivers who can show they have taken simple steps to secure their vehicles will not receive a penalty.”
Road 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”.