The biggest beneficiaries of the prospective sale will be financier Desmond and his fellow investors John Magnier, JP McManus and Denis Brosnan. Together with bloodstock millionaire Michael Tabor, a long time associate of Magnier and McManus, the four own 60% of the company. If the business achieves more than the £200m guide price, as now looks likely, the Irish investors will share in excess of £66m ( 96m), as Next Generation has debts of £90m.

Next Generation is being sold through an auction process overseen by investment bank UBS. It is understood Esporta, owned by private equity firm Duke Street Capital, is one of seven parties that submitted second-round bids for the company ahead of a deadline which falls this Tuesday.

Several of the bidders, including Esporta, have tabled offers in excess of £200m, the guide price specified by UBS in a memorandum circulated to over 30 interested parties in January. Those remaining in the process include "trade players, private equity groups and some property investors, " according to a source close to the process. It is understood British-Iranian property tycoon Robert Tchenguiz and investment firm Clerkenwell Ventures are among the bidders.

Several of those bidders have since visited Next Generation's 14 sites and attended presentations by the company's management team. The company owns all but one of its locations, hence the interest shown by developers such as Robert Tchenguiz. Tchenguiz's brother Vincent, also a property developer, bought the freehold interest in Next Generation's Chelsea Harbour gym two years ago.

Before the auction started in January, Esporta's chief executive Neil Gillis said the guide price was excessive and that Next Generation was worth no more than £150m.

Esporta promptly bid £180m for the chain but was knocked out of the process following the first round of bids. It has now come back to the table with an improved offer.

Next Generation was founded by former British tennis player David Lloyd and his son Scott. They are joined on the register by tennis legend Billie Jean King.