Sir James Dyson leans back in his chair, places his hands behind his head and looks out through the glass wall of his office, out across the huge open-plan interior of his company’s Wiltshire headquarters.

He’s considering the referendum result, having campaigned for Britain to leave the European Union.

“I thought it would be very close,” he says, his voice languid. “But I had absolutely no idea. In a way, I thought I was supporting the losing side, but I thought our arguments were better – and ultimately I was proved right.”

It’s the first time he has spoken since the Brexit vote and, although not gloating over his side’s victory, he is confident about the UK’s future.

“Absolutely I’m delighted to be out and don’t think we have to negotiate anything,” he says, when asked what happens next on the road to Brexit. “I know exactly what I would do if I was running the country. I would leave and then, over a period of time, I would negotiate things.”

He’s all for a quick exit and blow the consequences, having previously said that, despite the free movement of labour, EU nations aren’t supplying the highly skilled engineers his company needs. Instead, the company has to negotiate laborious red tape to source the brainpower it needs from the rest of world.

And commercially, Sir James – who is best known for his range of vacuum cleaners – doesn’t expect Brexit to deliver much of an impact.

“They are going to want to have a free trade deal with us more than the other way round,” he says of European soon-to-be-ex-partners.

“The imbalance of trade is £100bn so, even if we have to pay an import duty, it’s not much and it’s far less than currency swings.”

He pours scorn on the idea that the EU is single market anyway. “It is not. There are different languages, boxes, plugs, marketing and so on, different psychology, different laws. There’s a lot of cost involved.”

He also reveals that, in the confused days following the referendum, he was approached by David Cameron’s office to take a role in helping shape Britain’s exit from the EU, which he turned down.

“I sort of think I’ve done my bit,” says Sir James. “I was on a Prime Minister’s advisory group for five years. I’ve got a business to run and a lot of other things to do. I’m a practising engineer, not just a company owner. I am with my engineers all the time. My time is enormously taken up doing that.”

But he’s no Little Englander. Sir James employs 7,000 staff, about half of them in the UK, mainly at the company’s technology centre in Malmesbury, Wiltshire. The bulk of the remainder are in the Far East where Dyson does its manufacturing, but also some R&D work.

The latest phase of the Malmesbury centre officially opens on Wednesday and Sir James is keen to talk about that, but there’s one more thing to discover about his support for Brexit. Why would the owner of a £3bn global business want to weaken, rather than strengthen, international links?

“Sovereignty is the most important reason,” he says. “And I would say that, wouldn’t I? I started my own business. I wanted to be independent as a business. I don’t want to be part of a conglomerate.

“I see huge strength in independence, making your own decisions and choosing the people who run your own enterprise. Being subservient to Europe, having to do what Europe says, is entirely not in this country’s interest.”

David Fuller's view

Sir James Dyson’s reasons for not only favouring Brexit but also leaving quickly, in his own words: “I know exactly what I would do if I was running the country.  I would leave and then, over a period of time, I would negotiate things.”

That is fine for Dyson and no doubt many other UK businesses.  However, the UK is much more international than the EU.  The City has more overseas banks than any other financial centre in the world.  They like conducting business in London, which they also use as a gateway to Europe.  Many of these firms are not taking a longer-term view.  They want the convenience, immediate certainty and professionalism of London, with unrestricted access to the EU. 

Some other overseas firms, mostly non-financial, will feel similarly.  Notably, this includes Japanese automobile manufacturers as this service reported recently.  There is a good chance that the UK will be able to protect their access to EU markets, not least as German automobile manufacturers will not want any restrictions on their exports to the UK.  Moreover, as James Dyson also points out, the EU exports approximately £100bn more to the UK than we export to the EU. 

However, while there are many possibilities and even probabilities, there are few certainties today regarding future negotiations with the EU.  This is a challenge for Mrs May’s government.  It may also be an even bigger challenge for the EU. 

Here is a PDF of this interview with Sir James Dyson.  

Please note: Due to a lengthy appointment today, my review of leading stock markets will commence on Thursday.