Uber, which boasts 40,000 drivers in London and claims that 3.5 million people use the service, plans to appeal against the decision by the Transport for London (TfL), which said the USA -based company's approach and conduct was "not fit and proper" to hold a private vehicle hire licence.
"At the flick of a pen Sadiq Khan is threatening to put 40,000 people out of work and leave 3.5 million users of Uber stranded", Greg Hands, the government minister for London, wrote on Twitter late on Friday.
"I know that Uber has become a popular service for many Londoners - but it would be wrong for TfL to license Uber if there was any way this could pose a threat to Londoners' safety or security".
The American company has three weeks to appeal, and until the case is resolved, it can continue operating.
"As such we are lobbying for a stronger national licensing and enforcement approach to this issue".
TfL and Mr Khan came under fire from the business community yesterday for creating an impression that... "This ban would show the world that, far from being open, London is closed to innovative companies who bring choice to consumers".
TfL highlighted the company's approach to reporting serious criminal offences and to obtaining criminal record checks for drivers as factors in its decision.
A British government minister has criticised the London authorities for deciding to strip Uber of its taxi licence, a major setback to the US technology firm that has become a big player in the city's transport system.More news: DGMO to Pakistani counterpart: 'Indian Army reserves right to retaliate along LoC'
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TFL said it was revoking the license because Uber demonstrated "a lack of corporate responsibility in relation to a number of issues which have potential public safety and security implications".
"I want London to be at the forefront of innovation and new technology and to be a natural home for exciting new companies that help Londoners by providing a better and more affordable service", the mayor said.
London's traditional "black cab" drivers have long campaigned against the service, and welcomed Friday's decision. He told employees the company needed to act with integrity but that he did not believe Uber had done everything it was accused of in London. Uber has 21 days to lodge an appeal.
Uber said in response that it would challenge the decision.
The company says it has 3.5 million customers in the capital and almost 550,000 had signed up by Saturday afternoon.
"Uber operates in more than 600 cities around the world, including more than 40 towns and cities here in the UK".