Our Politics newsletter is now daily. Join thousands of others and get the latest Scottish politics news sent straight to your inbox. Subscribe Thank you for subscribing We have more newsletters Show me See our privacy notice Invalid Email

Claims Britain will enter a new economic boom after Brexit were ridiculed last night after it emerged hundreds of Scots firms are already being punished by ­“vindictive” Donald Trump .

The SNP said the US president proved he is unpredictable by slapping trade tariffs on key ­products, including whisky, in October.

Independent research by the Scottish ­Parliament suggests about 600 companies are caught up in the trade fight between Trump and the European Union, with Britain as a member.

Yesterday, the US ambassador to Britain, Robert Johnson, brazenly predicted quitting the EU will be like a return to the “roaring 20s”.

The label refers to a period of rapid growth after the devastation of World War I.

However, the diplomat carefully left out what happened at the end, when the world stock markets crashed and economies were ruined in the depression.

The ambassador made the claim in an interview on future trading between the UK and US.

He said: “I’m very ­optimistic. I’m an ­American but, even by my standards, this is really an amazing ­opportunity for this country. You have a clear direction, you have really good leadership fired up to get something done. So yes, a Roaring 20s, absolutely.”

He described the mood at the White House as “very positive”.

The SNP MSP for Caithness, Sutherland & Ross, Gail Ross said: “Hundreds of Scottish exporters have been hit by US tariffs, with the US taking an ­unpredictable, vindictive approach to trade ­negotiations.

“It beggars belief that the Tories want to rip up our trading relationship with Europe so they can cosy up to Donald Trump.

“They should be careful what they wish for.

“Scottish producers are the subject of ­international admiration but Brexit poses an ­enormous threat to our exporters.

“Scotland must not be dragged into this race-to-the-bottom trade deal – cut adrift from our international allies against the wishes of the Scottish people.”

Holyrood researchers said a shock 25 per cent tariff has hit a broad variety of Scots products.

Whisky, cheese, wool, shortbread and cashmere firms are ­disproportionately affected in Scotland. The charge also covers books, butter, seafood and fruit.

It was all part of a wider response to the EU on about £5.8billion worth of imported goods.