Ridesharing company Uber has lost its license to drive passengers in London.

Transport for London (TfL) said it had identified "a pattern of failures" that placed passengers at risk. It said 14,000 trips taken recently involved unauthorized drivers who were able to pass themselves off as other Uber drivers.

Uber said it would appeal the decision not to renew its license, the report said, describing it as "extraordinary and wrong." It can continue to provide services in London while the appeal is heard.

"We have fundamentally changed our business over the last two years and are setting the standard on safety," said Jamie Heywood, Uber's general manager for northern and eastern Europe. "We have introduced new safety features in the app for riders and drivers, introduced free accident and injury protection for drivers, improved our governance and compliance. We think this decision is wrong and we will appeal."

(TfL) said it "has identified a pattern of failures by the company including several breaches that placed passengers and their safety at risk. Despite addressing some of these issues, TfL does not have confidence that similar issues will not reoccur in the future, which has led it to conclude that the company is not fit and proper at this time."

(TfL) said that in September Uber was granted a two-month license as further information was required on these issues, some of which emerged late in the process of its reapplication. "A key issue identified was that a change to Uber's systems allowed unauthorized drivers to upload their photos to other Uber driver accounts," it said. "This allowed them to pick up passengers as though they were the booked driver, which occurred in at least 14,000 trips - putting passenger safety and security at risk. This means all the journeys were uninsured and some passenger journeys took place with unlicensed drivers, one of which had previously had their license revoked by TfL. Another failure allowed dismissed or suspended drivers to create an Uber account and carry passengers, again compromising passenger safety and security."

It added, "Other serious breaches have also occurred, including several insurance-related issues. Some of these led TfL to prosecute Uber earlier this year for causing and permitting the use of vehicles without the correct hire or reward insurance in place."