Uber contends in a court case it is "fit" to operate in London, after regulators last year stripped it of a license that could halt its presence in the British capital.
The regulatory agency Transport for London accused Uber last year of showing a "lack of corporate responsibility" in relation to "public safety and security," and failed to renew a license that would allow the U.S. ride-hailing service to operate in London.
Uber has been allowed to operate in London since it appealed the ban in October. Chief Executive Dara Khosrowshahi has visited London and met with the regulators to try and placate concerns, but the agency has not changed its stance.
Uber was headed to Westminster Magistrates' Court on Monday to kick off an appeal to overturn the ban. The hearing is likely to last several days.
Uber has agreed to report serious incidents to the police rather than leaving it up to riders and drivers to do so. In January, it introduced a mandatory six-hour safety break for drivers after 10 hours of work.
London is one of Uber's most crucial markets. More than 3.6 million people in London regularly use the Uber app, and around 45,000 drivers use the service.
To prove to regulators that it has changed, the ride-hailing giant is seeking an 18-month license rather than the five-year one it had requested last year.
Even once the judge makes a decision, either side could theoretically appeal again, meaning the battle over Uber's future in London could continue after the court hearing.
Uber has faced backlash in many major cities in Europe from established taxi firms and regulators.
CEO Dara Khosrowshahi took over the reigns last year from founder Travis Kalanick, whose leadership was fraught with scandals involving allegations of sexism and bullying. Khosrowshahi has been cleaning up the company, particularly as it prepares for a massive initial public offering in 2019.
Khosrowshahi told CNBC in a recent interview that Uber is on track to go public next year.