London's black cabs are on the war path against innovative taxi app service Uber, promising to cause widespread disruption across the capital in early June.

The Licensed Taxi Drivers Association (LTDA) argue that Uber's drivers are using an app to calculate fares. It is currently illegal for private vehicles to be equipped with taximeters.

However, Transport for London (TfL) have taken a very different view. TfL has, so far, not intervened because there is not "some sort of connection between the device and the vehicle".

Instead, Uber drivers are using the app for data about the time and distance of the journey travelled, which is not illegal.

The LTDA's general secretary Steve McNamara, told the BBC:

Transport for London not enforcing the Private Hire Vehicles Act is dangerous for Londoners. I anticipate that the demonstration against TfL's handling of Uber will attract many many thousands of cabs and cause severe chaos, congestion and confusion across the metropolis.

London is the latest in a string of European cities where established taxi operators have attempted to clampdown on Uber.

In April, a Belgium court ruling found Uber's operations illegal and threatened €10,000 fines for every ride. The ruling came after a series of protests by Brussels' minister for public works and transport Brigitte Grouwels along with several taxi companies, who had accused Uber of violating taxi regulations.

Berlin was quick to follow, serving the San Francisco-based company with an injunction for supposedly hurting competition. The injuction was brought forward by none other than Richard Leipold, a taxi operator and chairman of the city's taxi association.

In France, Uber has been subjected to the so called "15-minute" law, which requires taxi apps to wait 15 minutes after customers place a booking to pick them up.

However, this has not been enough to appease the militant taxi unions of Paris. The French capital's taxi groups have since been lobbying for a doubling of the regulation to a "30-minute" rule.

