UBER is unlawfully denying workers’ rights to its cab drivers, a major union said yesterday as it kicked off a landmark employment tribunal against the firm.

The trendy cab brand insists that it is merely a technology firm and that drivers are self-employed.

But drivers’ union GMB, which is taking Uber to the tribunal through lawyers Leigh Day, said that was “bogus” and the drivers are effectively employees.

The case will determine whether drivers are entitled to holiday pay, a guaranteed minimum wage and breaks. It is seen as a major test case for whether workers in what is termed the “Uber economy” of casualised labour will be able to gain basic rights at work.

GMB national secretary Justin Bowden said: “Uber is a multinational, multibillion-dollar company and GMB believes it is unlawfully denying its drivers fundamental rights which are designed to ensure workers can enjoy a minimum standard of living.

“GMB is proud to be bringing this claim against Uber and challenging the growing and pernicious practice by companies of wrongly claiming that workers are self-employed.”

Last year GMB calculated that a member working exclusively for Uber received just £5.03 an hour in August once costs and fees were deducted from takings.

The union says Uber also regularly deducts money from drivers’ accounts without notice when customers complain.

Leigh Day lawyer Annie Powell said: “We will argue that Uber exerts significant control over its drivers in order to provide an on-demand taxi service to the public.

“If Uber wishes to operate in this way, and to reap the substantial benefits, then it must acknowledge its responsibilities towards those drivers as workers.”