A billion-pound Twenty20 blueprint to rival the Indian Premier League (IPL) will be discussed by the England and Wales Cricket Board (ECB) next week amid fears that the new contest threatens the future of the smaller county sides.

The controversial plan, involving only nine teams based at the Test-match grounds, was leaked yesterday before play started in the first npower Test between England and South Africa at Lord’s.

The idea for the new competition — which would be called the New T20 and become by far the most lucrative in the English game — was drafted by Keith Bradshaw, the MCC chief executive, and David Stewart, the Surrey chairman, in a 21-page document. They have calculated deals over ten years with an estimated £85 million generated annually through enhanced broadcasting contracts at home and abroad, and match-day and commercial revenue. Rights to each team — linked to a city, ground, region or county — would be sold for an average approaching £50 million each.

Paul Russell, the chairman of the Domestic Structure Review Group, which has been re-examining the county programme beyond 2009, dismissed the sums as “a foray into flights of fantasy and fairytale economics”.

Bradshaw, though, has insisted that the sums would be verifiable. First-year profits are estimated at £47 million and money would be distributed among all 18 counties, as well as other groups, including the grass roots of the sport. The competition would last for 25 days in June and July from 2010, sandwiched by a barely altered domestic programme.

Three or four overseas players would be allowed in each side and teams would be bought at auctions similar to the IPL affair in Bombay this year, with a salary cap of £1.5 million. Teams would be allowed a local icon player, such as Andrew Flintoff, in the team based at Old Trafford.

Although the ECB would have a role in running the games, through umpiring, anti-corruption measures and sanctioning the tournament, for example, the new event would be owned and organised by a new company called New T20 Limited.Giles Clarke, the ECB chairman, was surprised by the proposals and responded almost dismissively after confronting Bradshaw earlier in the day. “It is not a document I have been involved with in the slightest,” Clarke said. “Quite a lot of it is not necessarily going to receive a welcome from me.

“A great deal of work has been done on documents that are fully inclusive of all 18 counties and personally and as a board we are clear on that. There have been all sorts of ideas pushed around in recent weeks and months, most of them of debatable economic validity.” However, the document states: “Aside from the standard of grounds as a qualifying criterion, an 18 or more team competition dilutes star players too widely, reducing the overall standard of all teams. It also increases the risks of meaningless matches restricting opportunities to maximise broadcast and commercial revenues.”

The authors believe that the tournament will give an optimum television slot timed for both UK and Indian markets at the height of summer when there is no other domestic — and little international — cricket in the world. They also point to high spectator and broadcast audiences for sport in England.

The project team behind the document includes Hampshire and Lancashire as well as MCC and Surrey, who were thwarted in attempts to stage an IPL exhibition match this season. Bradshaw and Stewart were also assisted by Deloitte’s Sports Business Group and Charles Russell LLP, a firm of lawyers.