Jaguar Land Rover's parent company Tata Motors has revealed that the two brands made a 10-month loss of £280m.
Total global sales for the brands dropped by 32% in the 10 months to March 31.
Tata also said that further shutdowns were likely at Jaguar Land Rover's factories in Castle Bromwich, Coventry, Solihull and Halewood, Merseyside.
Jaguar Land Rover currently employs 14,500 people, having made 450 redundancies at the start of the year.
A spokesman for Jaguar Land Rover said the business was continuing talks with the Government into the possibility of some form of financial assistance.
Tata bought Jaguar Land Rover for £1.7bn in June 2008 from Ford.