The London Taxi Drivers Association (LTDA) is to launch private legal action against minicab drivers using the Uber app, according to a report  in the Guardian. The car booking app has spread across the globe since its launch in San Francisco in 2010, causing concern among traditional taxi services in the 115 cities in which it operates.

The LTDA is issuing court summons for six minicab drivers who use Uber, contesting that it is illegal for private-hire vehicles to be fitted with meters. If these test cases decide that the app falls within the legal definition of a meter, it could affect hundreds of other Uber drivers who operate within London.

Transport for London, which is in charge of regulating private-hire vehicles, does not believe installing Ubers equipment in a car constitutes a breach of the law but is seeking a binding decision from the high court on the matter. They have also called for co-operation between Londons taxi drivers and private-hire drivers.

Steve McNamara, LTDAs general secretary, said, “It is crystal clear Uber are breaching the Private Hire Act” and called Transport for Londons move a stalling tactic designed to prevent his union from calling a judicial review.

The union already has plans to protest Ubers presence in the capital on 11 June, when it will park black-cabs in Parliament Square, Trafalgar Square and along Whitehall, potentially reducing the centre of London to gridlock.

Licensed taxi drivers across Europe and America have reacted in a similar fashion to the growth of taxi hailing services, with an Uber car attacked and major roads brought to a standstill by demonstrations in Paris. Berlin, Brussels, New York and Toronto have also seen protests and legal action taken against services.

This month saw Uber launched in Manchester, while the companys chief executive, Travis Kalanick, recently confirmed it was set for a new round of fundraising that could see the company valued at up to $17bn (£10bn)