Jim Ratcliffe, one of Britain's richest billionaires and a prominent Brexit supporter, said Wednesday he will open a new auto plant next to one being abandoned by Ford in Wales.

The factory in Bridgend is already under development, with plans to initially hire 200 people before growing to 500 employees within four years, Ratcliffe's Ineos industrial company said in a statement.

"The decision to build in the UK is a significant expression of confidence in British manufacturing, which has always been at the heart of what Ineos stands for," Ratcliffe said in the statement.

The Welsh government is due to partially subsidise the company's total investment of £600 million ($750 million), although the exact amount of state support has not been disclosed.

Ineos intends to use the plant to build the Grenadier, its own "utilitarian" four-wheel rival to the BMW-owned Land Rover Defender.

Ford said in June that it would shut down its engine plant in Bridgend next year, eliminating 1,700 jobs due to declining plant activity.

Ineos Commercial Director Mark Tennant told AFP that the Bridgend location made economic sense, with the Ford layoffs creating a new pool of skilled workers.

"In Bridgend, we have a very strong industrial heritage and expertise," Tennant said in an interview.

"It was important for us to build in the UK, it was always an aspiration," he added. "The 'Made in UK' is important for us."

The Bridgend-assembled vehicle will run a BMW engine made in Germany and ride a chassis constructed in Portugal.

The decision by Ineos runs counter to the latest market trends, which have seen UK plants being shuttered due to a global auto industry downturn and the uncertainties created by Britain's withdrawal from the EU.

Industry estimates put the cost of Britain leaving the EU bloc without a negotiated agreement with Brussels at £70 million a day.

But Ineos communications chief Tom Crotty argued that the Grenadier would be a "niche" vehicle with a well-defined target market made up of farmers and small businesses.

Initial annual production has been set for 25,000 vehicles.

"Time is on our side," said Crotty, stressing that most Brexit-related disturbances would probably occur immediately after Britain's departure, which is now set for October 31.

The Bridgend plant is not due to open for another two or three years.

Among the most recent automotive departures from Britain, Honda in February announced the closure by 2021 of its plant in Swindon, west of London, putting 3,500 jobs directly at risk.

Both Honda and Ford have been careful to avoid blaming their decisions directly on Brexit, which remains a highly-charged issue in UK politics.

Copyright AFP. All rights reserved.

INEOS's proposed new factory
A computer generated image of INEOS's proposed new factory in Bridgend, south Wales Photo: INEOS INEOS