The rate at which Twenty20 [Images] is climbing the popularity charts worries former Test umpire Dickie Bird, who fears the shortest version of the game may end up killing county cricket in England [Images].

Bird says there might just be "no county cricket in four years' time" as administrators of the game continue increasing the number of Twenty20 games which have been massive crowd pullers.

"Twenty20 puts bums on seats and has done a lot for the game, it has brought youngsters into cricket ... but what worries me is that it could kill county cricket," Bird was quoted as saying by the Daily Telegraph.

"We can't lose county cricket because that's where our next generation of Test cricketers will come from," he added.

The spectator-count in county matches has been dwindling with each passing season and Bird says if Twenty20 keeps getting the kind of promotion it is getting right now, the day will not be far when no one would turn up for the elite domestic event.

"... it's suffering with spectators and they're just flooding the market with more Twenty20 games and tournaments," Bird explained.