The Super League Nations Cup, which takes place tomorrow at the Longines Royal International Horse Show at Hickstead, in West Sussex, is likely to be the last one unless £250,000 in sponsorship is raised by the end of the month.

Hickstead is one of eight European venues that hold a Super League event, involving the top eight showjumping nations, but, under sweeping changes proposed by the International Equestrian Federation (FEI), its chance of retaining the event is under threat. To upgrade the Nations Cup event - and to try to match the new Global Champions Series, which offers higher prize-money - the FEI intends to reduce the number of venues to six, each of which must produce a purse of £250,000 for its grand prix.

While Aachen, in Germany, one of the eight venues, is flushed with sponsors and offers that level of prize-money, several of the other venues, which include Dublin, La Baule, in France, Rome and Rotterdam, have a serious shortfall. The total prize fund for Hickstead's grand prix - the King George V Gold Cup, which takes place on Sunday - is £60,000.

“It's a nightmare. We've only got until the end of July to come up with the money,” Daisy Bunn, the sponsorship director and daughter of Douglas Bunn, the founder of Hickstead, said yesterday. “This is a battle not just to keep the Samsung Super League at Hickstead, but to keep this one international competition in the country. With the London 2012 Olympics coming up, it seems ludicrous that the event which offers the best preparation for our team may be taken away.”

Forty-five thousand people regularly attend the meeting at the famous venue, for which the Nations Cup, first held in Britain in 1929, is the main attraction. The event started at Olympia, in London, and moved location several times before being given a permanent home by Bunn in 1992. More than £500,000 has been spent keeping Hickstead's facilities up to international standard and FEI officials who looked at the venue this year described it as “perfect”.

David Broome, the former Olympic rider, who is chairman of the performance development and international committee of the British Show Jumping Association (BSJA), is appalled at the idea of Britain losing its Super League status. “It would be criminal if we didn't hold a Super League Nations Cup in this country, both for our prestige and the sport's standing,” he said yesterday. “Hickstead has been a wonderful place for it, but if they can't continue with it, the federation should see whether there could be anywhere else in the country who might bid for it.”

Jacky Wood, chief executive of the BSJA, believes that to be unlikely. “It's our understanding that the FEI feel Hickstead is the only suitable venue,” she said yesterday. “We are supporting Hickstead's bid and doing everything possible to find a sponsor.”

The event carries extensive television coverage - it is being shown live on Sky Sports - but these are harsh times to be looking for sponsorship. Daisy Bunn said that the only response to date has been from a member of the public who called at the office this week and donated £10,000.

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