AFL clubs are on the verge of a significant dispute with their players over a threat to the staging of their annual best and fairest presentations.

The stand-off is over a condition in the new collective bargaining agreement stipulating AFL players must take six weeks of their annual nine weeks leave uninterrupted, meaning many would be unavailable for the most significant club event on the off-field calendar as it is scheduled at present.

The Age understands clubs plan to strongly challenge the new industrial clause at talks to take place on Thursday between the AFL and its 18 club chief executives. The clubs in turn have been advised by the players' union to reschedule their best and fairest counts.

As more contentious fine print emerges in the recently completed deal between the AFL and its players' association, the disruption to their annual night of nights has left several clubs mutinous. One angry chief executive said: ''This threatens to destroy the culture of football clubs.''

Most clubs schedule their best and fairest over September and October depending upon ladder position, meaning teams that miss playing finals tend to take four weeks' break, return to attend the club function, and then take another four weeks along with one week over Christmas.

Collingwood boss Gary Pert said: ''The best and fairest is the signing off for the year for the entire club - for the players, the staff, the members and all the supporters.

''If the rules are implemented as they currently stand, I can't see how clubs with overseas or other special training camp commitments can realistically schedule their best and fairest until late January or early February. So I can't see how this proposal can work.''

The Brownlow Medal count, which falls amid the uninterrupted six-week break for most players, has been exempted from the new rule.

Pert, who sat upon the AFL advisory committee during the protracted CBA negotiations, said he had voiced his concerns at the time.

AFLPA chief executive Matt Finnis has met with all AFL clubs except the Gold Coast and is understood to have communicated in several tense club talks that the clause was approved by the AFL and would stand.

Finnis told The Age: ''What we are doing is putting an end to the practice of clubs bringing back players after four weeks for testing or training and then giving them another break. It's something Andrew [Demetriou] and I agreed on.''

Finnis said the AFLPA was prepared to be flexible in 2012 given the late deadline, but added that clubs would have to be flexible regarding best and fairest functions in the future.

Thursday's AFL briefing was called earlier this month, and will also cover club concerns over the league's new media company, free agency, the current legal fight with Optus, the latest on poker machine legislation and what would be expected from the clubs under the new broadcast rights agreement.

The clubs also recently learned they faced hefty injury payments not only for career-ending injuries, but for lower-listed players who became injured in second-tier competitions. Every club will next season also have to devote $852,000 in marketing and other commercial payments to players outside the salary cap - the former ASA allowance - which is an increase of $240,000 from 2012.

Several clubs have already signalled their disappointment in the lack of flexibility in the six-week clause to football operations boss Adrian Anderson and remain hopeful of some support from head office. For several clubs, best and fairest counts are also revenue raisers, and the AFLPA's suggestion they schedule several alternative dates depending on the team's final ladder position was not well received.

Essendon and Carlton are also reportedly furious at the revelation the traditional staging of their best and fairest functions has been threatened, while Richmond chief executive Brendon Gale said: ''It's an issue. The impact this is going to have on our best and fairest is a real issue.''

Hawthorn boss Stuart Fox said his club had alerted its concerns to the AFL. ''We think this presents some real challenges for clubs. We've raised the issue with the AFL and we believe they've gone back to the AFLPA.

''I don't think it's unreasonable given the obvious challenges with bringing everyone back together later in the year when the season has long finished.''

West Coast chief Trevor Nisbett pointed out that not only was the vote for the club champion the biggest event on every club's social calendar, but also the late timing of best and fairest results would come too late for future budgets involving player bonuses and other salary cap estimates.