An immediate investigation has been called for by the Liberal Democrats’ transport spokesperson in the London Assembly.

Since Brexit, the UK cannot automatically access the personal information of EU residents, and five European countries have accused TfL of illegally obtaining the information.

France, Germany, Belgium, Spain and the Netherlands have claimed that the details of the drivers were acquired by Euro Parking Collection, the contractor who enforces Ulez overseas.

Over 100 French drivers are suing TfL due to the alleged fraudulent means used to acquire their personal information, whilst truck drivers from the Netherlands and challenging over £6.5milliion worth of fines.

Some of the vehicles fined have been misclassed as heavy goods diesel vehicles, which can incur penalties of up to £2,000 a day.

Belgium MP Michael Freilich has accused TfL of using European drivers as a “cash cow” in order to obtain money through incorrect fines.

Many of the drivers who were given fines were not aware that they had to register their vehicles prior to coming to London. Therefore, those who planned a spontaneous trip to the capital were essentially guaranteed a fine.

Freilich said: “This is possibly one of the largest privacy and data breaches in EU history, but so far no concrete action has been taken while responsibilities are being shunted on to drivers.”

He has asked ministers to raise the issue during the current Belgian presidency of the Council of the EU.

TfL has justified the penalty notices as it was unable to determine whether the vehicles were compliant or not as they were not registered.

Responding to a Freedom of Information request asking about the policy, TfL said: “We use European Parking Collections (EPC) to carry out foreign enforcement on our behalf. They are provided with details of the vehicle and then carry out some additional checks. If they establish that the vehicle is compliant a PCN will not be issued. If compliance cannot be established then a PCN will be issued.

“If the keeper of the vehicle contacts EPC to confirm the vehicle is compliant, and provides supporting evidence, then the penalty will be cancelled and the records updated to mark the vehicle compliant. This ensures that if the vehicle is driven in the ULEZ again no penalties are issued.”