Why Indians abroad succumb to 'Modimania'
"Of all the world leaders who have visited Britain, only Nelson Mandela and the Pope have addressed bigger public gatherings than Narendra Modi's rally at Wembley," boasts a spokeswoman for the UK Welcomes Modi organisation.
It is billed as a grand community reception, and 60,000 Modi supporters - almost all of Indian origin - are expected to crowd into the sports stadium in north London on Friday afternoon.
It will be his first visit to Britain as prime minister and many in the Indian community have been eagerly awaiting this moment.
"People are going mad for Modi, Modi, Modi," says CB Patel, a London-based publisher and columnist and longstanding supporter of India's prime minister. "I call it Modimania."
Wherever Mr Modi goes - and he has spent a lot of time globetrotting in the 18 months he has been in office - he seeks to talk directly to the Indian diaspora.
The gathering at Wembley just a few days after the Hindu religious festival of Diwali is expected to be his biggest yet.
The organisers say they can't meet the demand for the free tickets.
The cost is being met largely by donations - 10,000 people are said to have contributed - along with businesses that are both supporting the event and paying to advertise.
Not all the 1.5m people of Indian origin living in Britain are cheerleaders for Mr Modi and his Hindu nationalist party, the BJP.
A Modi Not Welcome campaign is organising protests during his visit, complaining of religious intolerance and an autocratic style of government.
Part of his purpose, say these campaigners, is to create a worldwide network of Hindu right-wingers - something they regard as worrying.
But there is broad enthusiasm among the Indian diaspora for Narendra Modi. Here's why:
- Modi has actively sought support from Indian communities abroad, and that's something new; the Indian diaspora are more often made to feel guilty for turning their backs on the home country than embraced for their global influence and success. Even now, any Indian seeking to become a national of another country has to hand back their Indian passport.
- India's prime minister has praised the diaspora as part of India's "soft power" - standing alongside yoga and the Bollywood movie industry in giving the country global prestige and influence. No other Indian leader has spoken so warmly of the achievements of Indians abroad.
- Indian communities in Western countries are often high-achieving and prominent in business, technology and the professions; they tend to be sympathetic to Modi's business-friendly policies. "Indians worship money and want to become rich," says CB Patel, "and Modi's economic priorities are much admired by Indians abroad."
- Gujarati pride is also at play. Modi is from this western state, which makes up just 5% of India's population but is much more prominent in the diaspora. More than 600,000 people of Gujarati origin live in Britain; along with Punjabis, they constitute the greater part of the Indian-origin population.
- The BJP's landslide election victory last year was in part because Modi was seen as representing hope for a revitalised India; the welcome he has received in Western capitals, with Barack Obama personally nominating Modi as one of Time magazine's '100 Leaders', is relished by Indians abroad as a sign of India gaining global influence and authority.
- While the organisers insist that Indians of all religions, regions and backgrounds will be present at Wembley, Modi's success reflects a Hindu cultural revivalism which is at least as evident, some would say more so, among the diaspora as in India.
The courting of Indians abroad is in part about money. The 30 million Indians living outside the country contribute an estimated $70bn (£45bn) to the economy each year in remittances.
Narendra Modi has already taken steps to encourage diaspora investment in India, as well as making it easier for those with foreign passports to spend time in what many regard as their mother country.
Some wealthy Indians overseas are also said to contribute generously to political parties back home.
Political financing in India is notoriously murky, and views differ about how important diaspora money is to the BJP - but academic experts say there is little doubt that right-wing movements do well from this source of funds.
Modi meets Indians abroad:
- New York, September 2014: 30 members of the US Congress are part of an 18,000 crowd at Madison Square Garden, a venue more associated with rock stars
- Sydney, November 2014: 16,000 gather to hear Narendra Modi speak in Hindi at an arena in the city's Olympic Park
- Toronto, April 2015: Canada's prime minister introduces Narendra Modi at an indoor arena with 10,000 present
- Dubai, August 2015: 50,000 Indians living in the Gulf pack Dubai's cricket stadium for the biggest Modi rally abroad to date
- San Jose, September 2015: after a visit to California's Silicon Valley, Modi addresses 18,500 at an arena known as the Shark Tank after the local ice hockey team
While in London, Narendra Modi will want to remind David Cameron that India may prove a more reliable Asian ally than China, whose president, Xi Jinping, recently enjoyed a conspicuously successful trip to Britain.
As a head of government, Modi won't get the full pomp and pageantry that greets heads of state such as President Xi.
And while the British government's overture to China is seen as a bold and distinctive foreign policy initiative, there's not the same diplomatic buzz about the Indian leader's arrival.
But British MPs and political leaders - many of whom are being invited to the Wembley event - are bound to be impressed by Narendra's Modi's ability to mobilise large numbers of supporters.
It is not often a UK politician attracts a stadium-size crowd.
Andrew Whitehead, a former BBC India correspondent, is honorary professor at the University of Nottingham and at Queen Mary, University of London.