The U.S.-owned Haas Formula One team have furloughed most of their British-based employees, meaning half of the grid has now taken similar measures in response to the new coronavirus pandemic.
McLaren, Williams, Racing Point and Renault had already furloughed staff.
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Seven of the 10 teams are based in Britain, with only champions Mercedes and Red Bull yet to announce salary reductions.
The official F1 website said Haas drivers Kevin Magnussen and Romain Grosjean were also believed to have agreed to a pay cut.