Uber has launched an appeal against Transport for London's decision not to renew its operating licence.
The appeal was filed at Westminster Magistrates' Court on Friday after TfL rejected Uber's application over safety concerns.
The ride-hailing app's regional general manager Jamie Heywood rebutted the accusations, saying safety is Uber's "top priority".
"We are committed to Londoners and are working closely with TfL to address their concerns and requests, as we have since 2017," he said as the licence renewal was rejected last month.
TfL cited "several breaches that placed passengers and their safety at risk" as its reason for the licencing decision.
It found that a change to Uber's systems allowed unauthorised people to upload their photographs to legitimate driver accounts, enabling them to pick up passengers.
This resulted in 43 drivers making at least 14,000 uninsured trips.
Some of these drivers were unlicensed while one had received a police caution for distributing indecent images of children, TfL said.
Mr Heywood said: "We uncovered this issue, we raised this with TfL and put in place an effective fix.
"We are further strengthening our robust systems and processes through a new facial matching process which we believe will be the first of its kind in London."
Uber is allowed to continue operating in London until the appeal process is completed.
TfL first refused to renew the company's licence in September 2017 amid safety concerns.
After the firm appealed against the decision, it was handed a 15-month licence by a judge in June 2018.
When this expired in September, it was granted a two-month licence by TfL.
Uber says its London operation has 45,000 licensed drivers and 3.5 million customers.
