Billionaire Jim Ratcliffe's firm announced in December it would manufacture the model in Hambach, France, from late 2021 after a deal to take over a site run by Daimler, ditching plans to build a factory in Wales.

On Wednesday it said more than 130 second-phase prototypes will be tested in extreme environments around the world.

"We only have one opportunity to get this right and our quality and performance targets for the Grenadier remain paramount," said CEO of Ineos Automotive Dirk Heilmann.

"We won't cut corners."

(Reporting by Costas Pitas; editing by Alistair Smout)