The strength of sterling agains the euro and disappointing car sales have been blamed for a dive in Toyota's financial performance.
Ominously for the UK, the poor results have been accompanied by warnings from the Japanese manufacturer that it is unlikely to to authorise additional investment in this country while currencies remain unstable.
Toyota recorded a pre-tax loss of £52 million last year in the UK, compared with a profit of £19.1 million in 1998, according to the Financial Times.
Toyota is also said to be warning of "much worse to come".
A company spokesman said: "The currency problems with currency have persisted this year and the situation is worsening."