Analysts in United Kingdom (UK) are already anticipating heavy loss of revenue from Nigerian mega-spending shoppers ahead of the introduction of the £3000 UK Visa Bond which takes effect in November.

Data released this week by tax-free shopping specialists Global Blue, published by Financial Times of London, revealed that Nigerians are the sixth largest spending nationality of luxury shoppers in the UK, snapping closely at the heels of tourists from Thailand and Russia.

They are also the only group in the top 10 under imminent threat of the bond, which the government is set to pilot in November as a prerequisite for UK entry on all six-month visas issued to travellers from Nigeria, Ghana, India, Pakistan, Bangladesh and Sri Lanka.

Data from the Office for National Statistics suggest that the proposed bond could have a big impact on Nigerian spending in the UK. Of the 142,000 Nigerian visa applications in 2012, over two-thirds were for six-month visas, as many applicants want flexibility for multiple short-stay shopping trips.

Taking the other five countries into account, this could potentially affect 543,000 tourists on 2012 figures.

Early on a midsummer evening, the gilded halls of Harrods are heaving with shoppers. From the throngs gathered within the cool and cloistered accessories rooms to the exotic bustle of the Egyptian Hall, visitors from Nigeria are particularly plentiful.

"For many of us from Lagos, London is like a second home," says Nigerian national Biola Dosumu amid the lotions and potions of the Crème de la Mer beauty counter. "It's always our first port of call for shopping, particularly for more bling bling items which are harder to find back in Africa."

She might not flinch at dropping £3,000 on a designer handbag, but the prospect of splashing out the same amount on a cash bond to obtain a visa is something high spending visitors find insulting.

"Make no mistake, no one is interested in immigration hassle - if things get tougher, then Nigerians will definitely go elsewhere - over to Europe or perhaps to the US, where one can get more for their dollar," she says.

Global Blue's data show Nigerian spending rose 17 per cent in the first six months of 2013, measured against the same period last year, with the average spend per head rising to £628 from £505. Luxury retailers fear these gains will be reversed when the visa pilot is launched, driving wealthy shoppers on to the continent.

"What on earth is the point of us pouring all this money into our retail industry if we promptly usher potential visitors across the Channel?" says Mark Henderson, chief executive of British heritage brand Gieves & Hawkes.

"More protection is yet another step in the wrong direction and we're doing everything we can to make that clear to the government," said Michael Ward, managing director of Harrods.

Luxury retailers have long been campaigning for a more streamlined visa process for Chinese shoppers, the top foreign spenders in the UK.

Visitors to Europe who apply for a Schengen visa can cross multiple borders to 25 countries with one application. However tourists who wish to travel to the UK must apply separately for a second visa.

According to the UK China Visa Alliance, only 7 per cent of Chinese visitors to Europe also choose to visit the UK, meaning the majority of their luxury purchases are made in rival retail hubs such as Paris and Milan.

Gordon Clark, UK manager at Global Blue, said: "Visit Britain has estimated that an easing of current immigration regulations could add up to £1.2bn annually to the UK economy and create up to 24,000 jobs."