BORIS Johnson is keen to strike Britain’s first post-Brexit trade deal with Japan, Whitehall sources have suggested.

And aides to Shinzo Abe, the country’s Prime Minister, have reportedly told No10 that he too wants a deal as quickly as possible with insiders dubbing the potential agreement “EU plus plus” as it is envisaged to go further than the Brussels bloc’s recent deal with Tokyo, breaking new ground on the digital and financial services sectors.

The Cabinet’s high-powered EU Exit Strategy or XS Committee has met in Downing St to set out the main priorities of Britain’s trade negotiations 2020 strategy, including “most favoured nation” tariffs.

“The PM is very keen on the Japan deal now and thinks we can use it as a bit of a trailblazer,” declared one source. “It will really help to show Brussels as well as the rest of the world we’re ready to go.”

The XS committee of the Cabinet’s most senior ministers, chaired by Mr Johnson, has earmarked four countries – the US, Japan, New Zealand and Australia - as Tier One nations set for early trade deals in addition to the EU. Other countries have been bracketed as Tier Two; they include Canada.

Downing St has made clear the UK wants to tie up a trade deal with the EU by the end of the transition period in 2020 but has also said it is seeking to secure an agreement with the US “as soon as possible”.

Steve Mnuchin, the US Trade Secretary, rumoured to be London-bound this weekend, bolstered Mr Johnson’s position by saying that Washington wanted to agree a post-Brexit trade deal with the UK before the year’s end.

Describing Britain as America’s “number one ally,” he declared: “It would be at the top of the list of trade agreements. We look forward to getting that done this year.”

The language and tone is in stark contrast to Mr Mnuchin’s remarks at the World Economic Summit in Davos when he appeared to threaten Britain with more punitive tariffs on goods should, as it says it intends to, the UK press ahead with slapping a digital sales tax on US tech giants like Google and Facebook.

From next Friday, the UK will be out of the EU bloc and free to begin striking its own trade deals with foreign countries.

UK ministers believe Britain will be in a position to begin parallel talks with American and Europe but Brexiteers are keen to see a dual talks strategy in the belief that the prospect of a swift deal with the US will stop the EU from dragging its feet during talks.