Isuzu also has a role in designing the engine which is likely to be fitted across the Honda range, including new Civic (right ) and Accord.
Mr Keir said the company was determined not to rush the project in the same way as the ill-fated tie-up with Rover did with the Accord four years ago.
“Because of our reputation on engines, the last thing we can afford is to have one which is not right,” he said. “As it is something we are going to put our name to, it is going through extraordinary standard controls and development.”
The planned 1.8- or 1.9-litre diesel is unlikely to be introduced to the Honda Stream, the new seven-seater mini-MPV to be introduced into Britain next April. Built on the new generation Civic platform, the Accord-sized vehicle will go head-to-head with Vauxhall Zafira, Renault Scenic and Citroen Picasso.
“We plan to sell 4,000 in what is a substantially increasing sector,” Mr Keir said. “We see it as an incremental volume model.”
Japan is to export Swindon-built 3dr Civics next year. Mark Davis, head of Honda's UK car division, said: “Our first target must be to satisfy demand for 3dr Civics in the UK and then in Europe. Then, if there is excess volume, we will send cars to Japan.”