When Ken Livingstone, Mayor of London, launched the city’s three-month India Now festival by sailing a replica Taj Mahal down the Thames in July, his aim was not simply to look back on 60 years since independence, but to milk future ties with a booming south Asian economy.

The UK, India’s second largest trading partner, now counts the country as its third largest investor, from banks to post-production film companies, while the world’s biggest cinema industry shot 40 movies in London last year. With more than 200,000 Indians visiting London each year, Mr Livingstone plans to open mayoral offices in New Delhi and Mumbai in November.