At the moment, clubs can only call off matches when they have three or more players in a senior international squad. But the Football League has asked First Division clubs to say whether or not they would prefer Under-21 squads to fall into the same category.
If a majority of clubs are in favour of the change it will be introduced, but League officials, who were been receiving replies from clubs throughout yesterday, said the outcome will be close.
Chris Hull, a spokesman for the League, said: "It looks as though opinions are pretty evenly divided.
"Some clubs want to play their matches despite having players on international duty because they don't want to get into a situation where they are playing two matches in midweek at the end of the season.
"Other clubs feel their international players are an integral part of their side and that they can't play without them."