The 31-year-old MMA fighter applied to register his name as a trademark in order to sell clothing in Europe.

This was opposed, however, by the McGregor fashion label, founded by David Doniger almost 100 years ago and now owned by a Dutch company.

A member of Clan Gregor, Mr Doniger could trace his roots to the first kings of Scotland. He made his money as a maker of McGregor tartan caps, giving him enough to make the voyage to New York, where he started his firm in 1921.

Mr McGregor sought to register his name in 2017. The following year McGregor won an interim victory as the sale of the fighter’s clothing was banned.

He has now been prevented from registering the trademark following a ruling from the European Union Intellectual Property Office (EUIPO).

The legal team for the company said the public could become confused were the trademark to be allowed.

The EUIPO said: “The goods are identical. They are directed at the public at large, whose degree of attention during purchase is deemed to be average.”

It added: “There is a likelihood of confusion on the part of the public. It follows that the contested trademark must be rejected for all the contested goods.”