Microsoft faces a dispute in the U.K. over how it charges customers who buy cloud software services that rival its own Azure, the latest antitrust challenge to the U.S. tech giant’s approach to licensing.

Microsoft is in the crosshairs of a U.K. competition class-action style lawsuit that's seeking £1 billion (around $1.25 billion at current exchange rates) in damages. It revolves around accusations related to fees the software giant charged businesses and other organizations for licensing Windows Server when they were customers of rival cloud computing platforms.

Microsoft faces legal action in Britain over a claim that thousands of businesses using cloud computing services provided by Amazon, Google and Alibaba could be paying higher licence fees to use Windows Server software.

Microsoft was accused of unfairly overcharging customers of rival cloud companies including Amazon, Google and Alibaba Cloud in a U.K. lawsuit filed Tuesday.