LONDON - London’s transportation authority said Monday it would not renew Uber’s license to operate in the British capital over passenger safety concerns.

Transport for London said it identified "a pattern of failures" by the company, including several breaches that placed passengers and their safety at risk.

Uber promised to appeal the decision and operate "as normal" in London while the appeal process is underway.

A key issue identified was that a change to the ride-hailing company's systems allowed unauthorized drivers to upload their photos to other Uber driver accounts.

"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," the transport authority said in a statement.

This means all the journeys were uninsured and some passenger journeys took place with unlicensed drivers, Transport for London said Monday.

Another failure allowed dismissed or suspended drivers to create an Uber account and carry passengers. As a result, it has deemed Uber “not fit and proper at this time.”

In an emailed statement to NBC News, Uber called the decision “extraordinary and wrong," and promised to appeal it.

The company also said that it has audited every driver in London over the last two months and will soon be introducing a new facial matching process for drivers.

Transport for London said it recognizes the steps that Uber has put in place to prevent safety breaches, but it "currently does not have confidence that Uber has a robust system for protecting passenger safety."

London Mayor Sadiq Khan tweeted to say that he supports the decision, adding that he welcomes technical innovation in the city, but companies have to “play by the rules” to keep customers safe.

My statement on TfL's Uber decision. pic.twitter.com/uMDjoIlqOW — Mayor of London (@MayorofLondon) November 25, 2019

Transport for London said Uber now has 21 days to appeal the decision. It can continue to operate in the city until any appeal processes have been exhausted or withdrawn.

Uber’s future in London, one of its biggest global markets, was thrown into uncertainty in 2017 when the transport authority rejected its licence renewal request, saying that the company’s approach and conduct demonstrated “a lack of corporate responsibility” in relation to a number of issues that have potential public safety and security implications. Uber appealed the decision.

A British court granted Uber a probationary 15-month license in 2018 after convincing the judge that the company had made significant changes to its business and corporate culture.

In September, Transport for London gave Uber a two-month extension to “allow for scrutiny of additional information.” It also imposed new conditions on ride sharing, appropriate insurance and driver document checks.

In London, the San Francisco-based company has faced criticism from unions, lawmakers and the city’s black cab drivers.

Outside of the United Kingdom, Uber had faced regulatory battles in multiple U.S. states and around the world. It had also been embroiled in a long-running battle with its own drivers pushing for better workers’ rights.