Do the French make them more quickly?

Kosuke Shiramizu, the company's board member in charge of global production, told the Financial Times newspaper that Toyota workers in France were 20% more productive than those in the UK.

Toyota UK said the views expressed were personal and did not reflect Toyota's policy or practices.

Derek Simpson, joint general secretary of the UK's Amicus union, said the comments were "deeply offensive" and that the union would be asking Toyota to either elaborate or apologise.

Third most productive?

"This is an insult to workers who have been extraordinarily co-operative," Mr Simpson said.

"The company has made no complaints to the union or any request for any extra flexibility.

MOST PRODUCTIVE EUROPEAN CAR PLANTS Nissan, Sunderland, UK Ford, Saarlouis, Germany Toyota, Burnaston, UK Fiat, Melfi, Italy GM, Eisenach, Germany Source: World Markets Automotive productivity index

"It makes you wonder what Toyota wants from its workforce."

According to the World Markets Automotive productivity index, Toyota's Burnaston factory near Derby is the third most productive car assembly plant in Europe.

The company's Valenciennes, France unit does not appear in the top 40.

'Goofing around'

Mr Shiramizu also reportedly said that British workers were picky, less willing to adapt to different jobs and tended to "job hop".

He attributed what he said was greater productivity at Valenciennes to the relatively high level of unemployment.

"In France there are many unemployed people and so [those with jobs] tend to work harder," he was quoted as saying.

Mr Shiramizu also criticised Japanese workers.

"[In Japan] you tend to find people are not so willing to work, they like to goof around and take on European attitudes," he said.

Toyota stressed that it does not normally like to compare the productivity of its factories.

"Comparisons between plants are always difficult. There are huge differences caused by differing models, technologies and locations," the company said.

"Nonetheless, Toyota Motor UK is often quoted as one of the most efficient plants in Europe."