Last week it faced a new UK blow when its licence in Sheffield was revoked for allegedly failing to answer questions about its management. Uber put the ban down to an administrative error, saying the council had sent letters to the wrong address.
In London, the company is trying to patch things up with TfL. It recently flew its new chief executive Dara Khosrowshahi in to the capital for talks and he is likely to return in the new year. However, it continues to appeal the decision in parallel, a process that allows it to continue to operate.
Tomorrow's hearing at Westminster Magistrates Court is a first hearing, with full arguments expected to be heard at a later point in several weeks' time.
"We filed our appeal so that we can continue serving millions of riders and tens of thousands of drivers in London," a spokesman said. "However, we continue having constructive discussions with Transport for London in order to resolve this. As our new CEO Dara Khosrowshahi has said, we are determined to make things right."
More immediately significant may be the ECJ decision on December 20, the result of a challenge from Barcelona's licensed taxi organisation. Elite Taxi claims that Uber is operating a transport service, while the company says it is an "information society service".
In May, the court's top advisor sided with Elite Taxi, saying Uber should have to abide by local taxi laws. The company has said an adverse decision would not affect how it operates in most cities.