According to a survey by Private Banker International’s sister company WealthInsight, in association with Spears magazine, 90% of the world’s multi-millionaires are male.

The most equal country for millionaires is Portugal, where 24% of multi-millionaires are female, and Japan is the least equal with only 3.7% of multi-millionaires being female.

The survey shows that a number of developed liberal economies, including Japan, France and the United States, are below the global average in terms of the percentage of female multi-millionaires.

Oliver Williams of WealthInsight said: "There seems to be no correlation between emerging and developed countries in the top 10 female multimillionaire countries. However, if you consider that Hong Kong and Singapore are home to many of emerging Asia’s multimillionaires, it appears that most of the top 10 countries are in fact emerging markets. This is a startling realisation when you think that it is Western countries leading the way in promoting gender equality."

The United Kingdom sits 10th in Europe, and 15th in the world, for gender equality in the multi-millionaire population.

Josh Spero, editor of Spears magazine, said: "As always with the UK’s global performance, it’s a case of ‘could do better’ with the gender balance, sitting near the middle of the table. As our economic recovery takes hold, perhaps we should start thinking about trying to encourage women specifically to pursue entrepreneurial ideas. According to the Harvard Business Review, female entrepreneurs make 20% more revenue with 50% less investment, so helping women get into business is good for us all."