The League Managers' Association has been informed that the assistant referees 'must see air' - the exact definition - between a forward and a defender before giving offside this season.

Referees' spokesman Philip Don was at a meeting in London to let the LMA members know what subtle changes are in store for next season, with the offside rule and simulation, such as diving, being the two main topics.

The offside interpretation should make it even harder for players to be pulled up, encouraging attacking play.

At present strikers are onside if they are level with the last defender, but from this season they can go forward a few vital inches.

However, managers Glenn Hoddle, Gordon Strachan and Jean Tigana were uneasy with the FIFA directive.

After a discussion, when some bosses questioned the move and were told 'it was nothing new', a resigned Hoddle remarked: 'There is no point arguing, they have made their minds up already.'

Meanwhile, managers' leader John Barnwell has pledged his support for a clean-up campaign by referees - providing they display some tolerance in return.

Barnwell, who insisted the two sides must work more closely together, said his members will show some early-season goodwill after a record turn-out for disciplinary briefings.

The LMA chief executive said that more than 90 per cent of managers attended regional venues. Only those on foreign trips were missing.

They heard referees' bosses issue a series of warnings. It was announced that automatic red cards would be given for swearing at officials and there would be stricter control of technical areas.

Barnwell admitted: 'There's got to be a bit more respect and if an official is subjected to a premeditated, vitriolic outburst we support the action taken. So does the PFA. It is running a campaign on this and we're backing it.