General Motors and Toyota are raising their stockpiles of car component supplied from Asia and Japan through the Suez Canal.

Holding 10 days' extra supply of even a small proportion of the total will add significantly to supplier costs. Shipping supplies around the Cape would cost about 30 per cent more than the shorter route through Suez, according to Shingenobu Uchikawa, senior vice-president of Toyota Motor Europe.

Other carmakers including Ford's European division and PSA Peugeot-Citroen said they had taken no special action because they had little exposure to parts from Asia.