THE taxi drivers of London are famous for their black cabs, pricey fares and outspoken political commentary provided to passengers at no extra charge. On September 22nd they were given a new subject on which to hold forth when Transport for London (TfL), the capital’s transit authority, said it would not renew the operating licence of Uber, a ride-hailing app that cabbies loathe for poaching their fares. “Uber is the school bully finally going to the headmaster,” cheers Steve McNamara of the Licensed Taxi Drivers’ Association. But whether Uber will be banished from London’s roads remains to be seen.

TfL cites several reasons for its decision. First is Uber’s way of reporting serious crimes. London’s police force has accused the firm of not reporting six sexual assaults promptly last year, including one case in which the driver continued to work and then attacked another passenger. Second is the company’s approach to how drivers’ medical and criminal-record checks are obtained, a point on which TfL does not elaborate. Third, TfL is not satisfied with Uber’s explanation of how it uses Greyball, software with the capacity to hide information from regulators and law enforcers. (The company says it is not used for this in London, but there is evidence of its use to fool the authorities elsewhere.)

Uber’s new boss, Dara Khosrowshahi, has admitted that the company has made “mistakes” in London. But the firm argues that TfL’s case is overblown, pointing out that it already has a team that works with the police on investigating crimes related to Uber rides, and that the medical and criminal-records checks are conducted by third parties. It has vowed to appeal against the ban and will continue to operate during that process, which could take a year. Even if it lost, it could keep driving by registering its drivers with a council outside London.

Still, the proposed ban has shocked many Londoners. Uber has never been kicked out of a market as important as London, which sits alongside Paris as its biggest in Europe. London is seen as one of the most politically open places to the controversial firm. TfL helped Uber to set up legally when it arrived in 2012. The app now has 40,000 drivers and 3.5m users there.

Many Uber passengers accuse TfL of caving in to the cabbies, who are vocal lobbyists. But Gareth Edwards, a transport expert at the London Reconnections news site, is sceptical. Taxi drivers do not see TfL as a sympathetic regulator, he argues. Many still moan about a rule introduced last year that compels drivers to carry credit-card readers.

TfL is more fed up with Uber’s habit of bending the rules. TfL has a legal requirement to ensure that its private-hire car operators are “fit and proper”. Firms in other industries where this test is applied, such as finance, could face losing their licence if it emerged that they had failed to report a crime committed by a contractor. And allowing Uber to go on flouting the rules could eventually provoke legal action from other operators.

Under its previous boss, Travis Kalanick, Uber responded to clashes with regulators by lobbying politicians to overrule them, often calling upon its customers to join in. When TfL tried to tighten the rules under which Uber is regulated in 2015, the firm successfully lobbied the central government to intervene. It has already organised a petition of more than 800,000 signatories against TfL’s latest move against it.

But it may have met its match. Most regulators that Uber has defeated have small budgets. TfL’s is double Uber’s global revenues. And unlike other taxi regulators, it is solely accountable to London’s ambitious mayor, Sadiq Khan, who does not face re-election until 2020.

Mr Khosrowshahi plans to visit London to help negotiate a new licence. Mr Khan also wants to settle the dispute out of court. That may explain why cabbies have not got their hopes up too much. “They’re a big company. They’ll be back,” one shouts, while overtaking an Uber car in the city.