He argued that Britain’s existing strong trade links with Europe and the ease of doing business with the trading bloc meant a Brexit would cause a reduction in investment in the UK.
“The ability to grow your company with a market of 250 million people is enormous. I have stores across the whole of Europe and the fact they are in the same currency makes a huge difference,” he said.
SuperGroup, which is advertised by Wire star Idris Elba and led by chief executive Euan Sutherland, counts half of its exports to the EU.
Alongside his fashion empire, Dunkerton has a string of bars, restaurants and hotels.
It has also emerged that he doled out £30 million to staff before the flotation — including £500,000 to his PA, who still works for the business. He co-founded Superdry with James Holder in 2003 and sold £53 million in shares to fund his divorce in February.