Taxi firm Uber is to appeal to the Supreme Court after losing a case over the employment rights of drivers.
Earlier this month the Employment Appeal Tribunal (EAT) rejected Uber's argument over the status of employees.
Unions argue staff should be classified as "workers" rather than being self-employed, which would entitle them to rights such as holiday pay.
An Uber spokesman said: "We have this afternoon requested permission to appeal directly to the Supreme Court in order that this case can be resolved sooner rather than later."
Drivers James Farrar and Yaseen Aslam took a case to an employment tribunal last year, arguing they were Uber staff and entitled to holiday pay, paid rest breaks and the minimum wage.
After the EAT upheld the original tribunal ruling Tom Elvidge, Uber UK's Acting General Manager, said: "Almost all taxi and private hire drivers have been self-employed for decades, long before our app existed.
"The main reason why drivers use Uber is because they value the freedom to choose if, when and where they drive."