London's transport regulator stripped Uber of its licence to operate from the end of the month, affecting over 40,000 drivers in a huge blow to the taxi app.

"Uber's approach and conduct demonstrate a lack of corporate responsibility in relation to a number of issues which have potential public safety and security implications," Transport for London (TfL) said.

The final day of Uber's licence will be on September 30.

"Transport for London and the Mayor have caved in to a small number of people who want to restrict consumer choice," Uber said in a statement. "We intend to immediately challenge this in the courts."

Transport for London said Uber would be allowed to continue to operate while the appeals process was exhausted.

In London, Uber has faced criticism from unions, lawmakers and traditional black cab drivers over working conditions.

Globally, Uber has endured a tumultuous few months after a string of scandals involving allegations of sexism and bullying at the company, leading to investor pressure which forced out former CEO and co-founder Travis Kalanick.

The app has been forced to quit several countries including Denmark and Hungary and faced regulatory battles in multiple US states and countries around the world.

London Mayor Sadiq Khan said he backed the decision.

"All companies in London must play by the rules and adhere to the high standards we expect - particularly when it comes to the safety of customers," he said.

"It would be wrong if TfL continued to license Uber if there is any way that this could pose a threat to Londoners’ safety and security."