Uber isn't taking the revocation of its London license sitting down.

The ride-hailing service, which stands to lose tens of millions in revenue from the ban, is revving up its customer base to pressure London's authorities to reconsider the decision. Rallying its millions of customers to put pressure on regulators is a well-honed technique at Uber, which tapped its customer base in New York several years ago to protest a potential curb of its service.

The company is asking London customers to sign a petition called "Save Your Uber in London," which it created after London announced the decision on Friday. As of early Friday afternoon, the petition had received more than 220,000 signatures.

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Reactions among London residents ranged from disbelief to support for the ban, which is set to go into effect next month.

Uber framed the ban as harmful to the livelihoods of the 40,000 licensed drivers who work for the service in London.

"This decision is affecting the real lives of a huge number of honest and hard-working drivers in London," it wrote in the petition. "This ban shows the world that London is far from being open and is closed to innovative companies, who bring choice to consumers and work opportunities to those who need them."

It's unclear how much revenue Uber receives from its London operations, but it's likely to be substantial given its customer base of 3.5 million people and huge fleet of drivers. While the company is private, it said its bookings in the U.K. topped $135 million in 2015, a number that's likely grown substantially since then, based on the company's overall growth rate.

The company recorded $6.5 billion in worldwide revenue last year, although it lost $2.8 billion as it invested in expanding its operations. Uber has an estimated valuation of $70 billion, with much of that based on its potential to rapidly expand and grow its business across the globe.

Uber has vowed to appeal the license revocation, according to Reuters, although it's unclear how likely it is to succeed. The company didn't immediately respond for a request for comment.

The London crisis adds to the mounting issues facing the ride-sharing company, which last month tapped former Expedia CEO Dara Khosrowshahi to lead the business following a series of scandals over a sexist workplace and the antics of ousted CEO Travis Kalanick.

London Mayor Sadiq Khan wrote on Facebook that he supported the city's transportation agency's decision to strip the license from Uber, citing safety concerns.

"All companies in London must play by the rules and adhere to the high standards we expect - particularly when it comes to the safety of customers," he wrote. "Providing an innovative service must not be at the expense of customer safety and security."

Uber is so relevant and encompassed into today's culture that if London ban it, it's actually gonna be the biggest shame. — demetrizia (@demetrizia) September 22, 2017

Since Uber entered London in 2012, the company has found itself at odds with the black cab industry, which organized gridlock-filled protests and argued that Uber's safety standards are lacking.

Londoners, though, flocked to Uber because of lower fares and the ease of using the app.

I need uber in london. It's cheap — Alex Lew, CFA (@alexlewyl) September 22, 2017

"I need Uber in London," one customer wrote. "It's cheap."