Last Friday Uber reduced prices by 15% in Taipei, Taoyuan, and Taichung, forcing drivers to earn less per ride, Apple Daily reported.

The ride-hailing app also increased the percent per ride that drivers return to the company. One driver said that on a NT$100 fare, he used to earn NT$80 but now can only receive NT$68.

Uber drivers in the affected areas have threatened to go on strike during the inauguration of Taiwan’s new president Tsai Ing-wen on May 20 as they claim the decision to reduce fares was unilateral.

Of course, drivers are unlikely to have much legal recourse as Uber was deemed illegal in Taiwan in 2014. The company has appealed, but the courts have thus far upheld the ruling and fined the company. As of April, Uber has accumulated NT$38.9 million in fines while its drivers have been hit with NT$12.4 million in fines for 290 violations, according to Focus Taiwan.

Earlier this month, Uber announced that it expanded its partnership with Alipay, Alibaba’s mobile payment app, to allow users worldwide to request and pay for their rides via the app. Users in Taiwan had been able to use Alipay for Uber rides since February of the year, The Wall Street Journal noted.