Uber Chief Executive Dara Khosrowshahi admitted the firm “got things wrong” Monday in a plea to London after the ride-hailing app was stripped of its license to operate in Britain’s capital city.

“While Uber has revolutionized the way people move in cities around the world, it’s equally true that we’ve got things wrong along the way,” Uber’s CEO said in an open letter published in the U.K.’s Evening Standard newspaper Monday.

Khosrowshahi added: “On behalf of everyone at Uber globally, I apologize for the mistakes we’ve made.”

His apology follows a decision by London transport authority Transport for London (TfL) to revoke the taxi start-up of its license to operate in the city last Friday.

The former Expedia CEO, who has served as Uber’s CEO for almost a month, said Uber would “work with London to make things right.”

TfL’s shock decision not to renew Uber’s private hire vehicle license dealt a huge blow to the start-up. Uber said it would appeal the decision, and has reportedly hired a top British lawyer, Thomas de la Mare, to fight its case.

Criticism has been leveled at Uber from all sides – including labor unions, politicians and traditional black cab drivers – over working conditions and regulatory concerns.

In a statement, TfL said: “TfL considers that Uber’s approach and conduct demonstrate a lack of corporate responsibility in relation to a number of issues which have potential public safety and security implications.”

London’s transport regulator holds that Uber failed to meet regulatory requirements in regard to reporting serious criminal offences involving its drivers, obtaining checks on its drivers and using a software tool known as Greyball, which allegedly allowed it to block regulators from gaining full access to the app.

British union GMB hailed a “historic victory” following the decision.

“This historic decision is a victory for GMB’s campaign to ensure drivers are given the rights they are entitled to – and that the public, drivers and passengers are kept safe,” Maria Ludkin, legal director at GMB, said in a statement last week.

The union had placed significant pressure on the San Francisco-based firm, particularly over the status of drivers as self-employed rather than employees of Uber.

London Mayor Sadiq Khan was among the Uber critics to come out in favor of TfL’s decision.

Khan claimed Monday that Uber had made “aggressive threats” to take London’s transport authority to court. As London’s mayor, he is also the chairman of TfL.

“London should be a place for new technology, London should be a place for that, but you’ve got to play by the rules, they’re there for a reason,” he said in an interview with BBC Radio 4.

“I’m quite clear about my role as the chair of TfL, I want companies that abide by the rules, I want companies that innovate and are the harbors of new technology, I want disruptive technology coming to London. But you’ve got to play by the rules. And so, if you play by the rules, you’re welcome in London. If you don’t, don’t be surprised if TfL take action against you.

Three quarters of a million people have signed a petition by Uber to protest its ban from operating in London. At 1:23 p.m. London time on Monday, the petition had reached 755,303 signatures.