Uber has launched a legal challenge against new rules in London which could require thousands of its drivers to take an English-language test, the company said.
The move comes ahead of measures to be introduced on October 1 by the regional transport authority, Transport for London (TfL), that will tighten regulation of the private hire industry in the British capital.
Uber originally backed the changes but said its opposition arose after more details of the regulations emerged.
“This legal action is very much a last resort," Tom Elvidge, general manager of Uber London said in a statement.
"We’re particularly disappointed that, after a lengthy consultation process with Transport for London, the goalposts have moved at the last minute and new rules are now being introduced that will be bad for both drivers and tech companies like Uber."
Despite facing regulatory challenges in numerous countries, Uber has so far expanded to more than 50 countries and is worth an estimated $68 billion.
The company's application for judicial review in London focuses on four of the new TfL rules.
They include the requirement that all private hire drivers not from majority English-speaking countries must prove their language skills.
While Uber supported an English- speaking and -listening test, it has argued that making drivers provide a certificate showing they have an intermediate level of writing and reading is unnecessary and costly.
Uber has more than 30,000 drivers in London and estimates thousands would be affected by the change.
Under the new rules private hire companies will be required to run an operating centre within London, which their passengers are able to call during a ride.
Uber's customer support centre is currently based in Ireland and it is against moving its operations to London.
Other rules opposed by Uber relate to drivers' insurance policies and the requirement that the company inform TfL of any upcoming changes to its app.
TfL confirmed it received a letter from Uber warning it of the legal challenge.
“We responded to Uber's letter and will be robustly defending the legal proceedings brought by them in relation to the changes to private hire regulations," a TfL spokesman said in a statement.