Mawhinney says a transfer window would hit small clubs hard

Fifa currently allow League clubs to trade among themselves during the season, but that could change.

And that could harm clubs which rely on selling players to balance the books.

"Transfer windows have been very bad news for the League. Our transfer values are roughly half what they were a few seasons ago," Mawhinney said.

He added: "We are in detailed negotiations with Fifa about this issue. I was in Zurich a few weeks ago and may well be back there in the autumn.

"At the moment Fifa are reviewing the situation - nothing has been decided. The fat lady isn't singing - she hasn't even got on to the stage yet."

Falling revenues have prompted falling player numbers with clubs hoping to get by on smaller and smaller squads.

"The drain of players is a big concern and if we don't have some success on our current discussions with Fifa then the number is going to increase further," warned Mawhinney.

The Football League has targeted a 30% increase in attendance figures by 2010, bringing an extra �75m into the game.