Toyota has sparked a fresh round of pressure on the Government to join the euro by forcing its UK suppliers to stop pricing in sterling.
Shoichiro Toyoda, honorary chairman and former chief executive of Toyota, called earlier this year for a clear UK commitment to the single currency.
Toyota exports the majority of cars built at its Burnaston plant near Derby to mainland Europe and wants parts makers to share some of the risk of currency fluctuation.
This month Nissan boss Carlos Ghosn met Prime Minister Tony Blair to warn that investment in the Sunderland plant might be reduced if Britain stayed out of the eurozone. Some form of financial package is likely to assist Nissan which is considering switching replacement of the Micra replacement to mainland Europe.
While Rover was part of its group, BMW executives repeatedly complained about the extra costs caused by the strength of sterling.
A Toyota spokesman said none of its UK parts suppliers had complained about the policy.