Boris Johnson has urged Jeff Bezos, the Amazon chairman, to use his influence over an electric vehicle (EV) company backed by the technology behemoth to build a gigantic new manufacturing plant in the UK.
An official Downing Street "readout" of their discussion released earlier this week made no reference to Rivian.
Executives from the EV manufacturer, which is in the process of pursuing a US stock market listing, visited the UK earlier this month to continue their evaluation of a site near Bristol.
Whitehall sources say the government is "desperate" to persuade Rivian to build its new factory in the UK, arguing that it would send a hugely significant message about the future of the country's automotive industry.
Rivian also counts Ford among its investors and is expected to make a decision about whether to give the green light to a factory in the UK or mainland Europe before the end of the year.
If the company does proceed in Britain, it would be likely to benefit from a substantial state support package.
Sky News revealed during the summer that Rivian had identified Gravity, a 616-acre campus near Bristol, as a potential site for a new manufacturing plant.
Rivian's biggest customer to date is Amazon, which has placed an order for 100,000 EV trucks, production of which is scheduled to start this year.
The government's decision to ban the sale of new petrol and diesel cars by 2030 and hybrid vehicles by 2035 has accelerated the need for a huge shift in manufacturing capability.
There remain significant concerns, though, that the provision of EV charging infrastructure will fail to keep pace with demand.
A government spokesperson said: "The UK continues to be one of the best locations in the world for car manufacturing, thanks to public and private investment into electrifying our supply chain, creating jobs and securing a competitive future for the sector.
"We regularly speak with automotive companies and potential investors."
Rivian declined to comment.
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