Its concerns included Uber's approach to reporting serious criminal offences, how drivers' medical certificates were obtained, how criminal record checks were carried out and its use of technology which allegedly helped it evade law enforcement officials.
Uber also faces being banned in Turkey after President Recep Tayyip Erdogan said earlier this month that the app was "finished", following an intense lobbying campaign from Istanbul taxi drivers.
These include: • Changes to its leadership such as the appointment of three independent non-executive directors to its United Kingdom boards.
It now proactively reports serious incidents to the Metropolitan Police.
After its application for a five-year licence was rejected last year, Uber is now seeking an 18-month one to prove to the authorities that it has reformed.
Black cab drivers had been celebrating TfL's decision because they believe Uber "faces next to no regulation" when they are "regulated to the hilt".
Uber's appeal hearing, which will consider if the company is "fit and proper" to operate in London, starts today and is expected to take several day before a decision is made - though the court battle itself could takes years to finally be resolved.
Mr Elvidge said that among the failings before he took charge were Uber's lack of clarity over whether the company or drivers accepted passengers, which has implications for workers' rights. He also admitted that the way regulator-dodging "Greyball" software was used in the United Kingdom was "fundamentally wrong".
'This was not good enough, it should've made multiple responses to further probing and further questioning to get to the ultimate response and that was wrong - that was inadequate'.
"We accept it was right", de la Mare told Westminster Magistrates Court, adding it had addressed TfL's concerns.
"TfL has concluded that Uber London Limited is not fit and proper to hold a private hire operator licence", it said in a statement at the time.
Uber may continue to operate in London for the duration of the hearing. The hearing will reportedly last around three days, according to Business Insider, and it's possible that the decision could still be appealed in a higher court.
The London licence is one of a number of headaches for Uber and its new chief executive Dara Khosrowshahi, who took over last August after founder Travis Kalanick was ousted following a series of scandals.