Earlier this month, Prime Minister Theresa May made her first post-Brexit diplomatic trip to India. Donning a flowing turquoise and gold sari, she was pictured walking through the temples of New Delhi barefoot – an effort that few national leaders would be likely to make.

This was a significant gesture. As Britain continues to debate what “Brexit” looks like, and with increasing anxiety over what the UK economy would look like after leaving the EU, May has been keen to indicate that Britain was “open for business”.

Back in London, Sanjay Shah, the owner of a small curry house in North London, sighed after reading about May’s visit to the subcontinent in an Indian newspaper (notably, her visit only filled a side column in the middle of the paper).

“She did nothing to promote small businesses like mine,” he says, adding that the Prime Minister was too busy “courting the rich from the cities”, referring to her visit to Bangalore, India’s booming version of Silicon Valley.

Shah is a committed Conservative. More Thatcherite than Cameronite, he joined the party in the mid-Eighties, in the belief that it was the Tory party that reflected the ethos of hard work and enterprise. And earlier this year, Shah voted to leave the EU, in the hope that Britain “would return back to the ethos of Margaret Thatcher”.

For Shah, this was particularly important for his business. The curry industry is worth more than £4bn annually, but for many restaurants, the ability to hire cooks and staff from South Asia has become particularly difficult, thanks to tighter visa restrictions brought in while Theresa May was Home Secretary.

The issue became a huge sticking point among many South Asian communities across the country, so much so that Priti Patel, one of the government’s most high-profile Asian ministers and a key figure in the Vote Leave campaign, promised to make the immigration system fairer for those outside the EU.

A few months after the Brexit vote, both Shah and the industry feel betrayed by the Prime Minister’s lack of commitment to bringing visa barriers down. “There are hundreds of restaurants closing every month,” Shah says. “I’m worried that I will also have to close down my business . . . I’ve spent 20 years working in it.”

It’s not just curry houses that are worried about Britain’s future with India. As the mood across the western world turns against immigration, British universities have also expressed concerns about the future of higher education funding.

Writing in the Times Higher Education supplement, University of Sheffield vice-chancellor Sir Keith Burnett warned May that her visa policy towards Indian students was “insulting” and had resulted in a 50 per cent decline in students choosing to study in the UK. That gap is likely to widen as universities in the EU look to take advantage of Britain’s Brexit woes by attracting talented Indian students.

Britain’s relationship with the subcontinent has long faltered. Foreign visas are partly responsible for this – the issue has been prevalent since David Cameron came into office in 2010 and, despite repeated pledges to reform the rules in order to attract more professionals, the system has only become more arcane.

But there’s also a wider cultural trend taking place in India, which could be profound in shaping its relationship with the UK. This can be best explained through Bollywood. The UK has long played a significant role in certain genres of Bollywood film, in depicting the metropolitan Indian.

Famous Seventies films including Purab Aur Paschim (“East and West”) and Dilwale Dulhania Le Jayenge (“The Braveheart will take the Bride”) both depict London as a land of hope and dreams for the transnational Indian. Other Bollywood films, including the smash hit Kabhi Khushi Kabhie Gham… (“Sometimes There’s Happiness, Sometimes There’s Sorrow”), set in 2001, depict distinctions between the old values of Indian parents against the metropolitan liberal values of their London-based children.

In recent years, however, the focus on London in Bollywood has depleted, and few major blockbusters have used the UK as their backdrop – opting instead for foreign locations in Australia, America and the Middle East, where the market for Bollywood continues to thrive. There is little research to suggest why this is the case, but it could be that London, and indeed the UK, may be becoming less important to modern Indians than it used to be.

Indeed, as India continues to grow, and its young metropolitans continue to flourish, new partnerships with the rest of the world may simply provide young Indians with more opportunity compared with an inward-looking Britain with growing anti-immigrant sentiment.

This has left Britain on the back foot – not just for its dealings with India, but for how it plans to negotiate with other non-EU countries on trade. During the EU referendum campaign, many on the Leave side harked back to the colonial era when talking about trade with India. The reality of modern India is far different from this nostalgic fantasy. Britain can seek to return to its former colony, but must realise that it is no longer the master, and is in no position to call the shots.