The "level of panic" in the United Kingdom around Brexit is "not justified", a former top trade adviser to Donald Trump has warned.

Stephen Vaughn, who served as the President's acting trade representative before becoming general counsel on trade, told the BBC that the British have "enormous amount of leverage" in a potential trade deal with the US.

This comes as ministers hail official figures showing that America has leapfrogged Germany to be he biggest single supplier of goods and services to the UK. In the last year, imports from the US increased by 14% and are now worth £78.2bn, with British consumers purchasing goods from the US at record levels.

At the same time, exports to the US have also reached new heights in the last year. British overseas sales totalled £121.6bn as trade between the two countries reached £199.7bn – a record high.

“Now that the US is our largest market for both exports and imports, there has never been a better time for us to make the most of this golden opportunity and deliver a free trade agreement with the US," said trade secretary, Liz Truss, who is currently visiting New York and Washington.

Meanwhile, Michael Gove has discussed the prospect of holding a bank holiday on November 1 to mitigate the fallout from a no-deal Brexit, as Government special advisers cancel their holidays to step up Whitehall preparations.

The Chancellor of the Duchy of Lancaster, who is in charge of no-deal preparations, said the Government would consider the idea during a meeting with business leaders on Thursday.

A bank holiday would mean that the financial markets would remain closed for 24 hours after the UK left the European Union without a deal, a move which some believe could soften the immediate impact on the economy.