Saturday's vote at the GAA special congress to consider the deletion or suspension of Rule 21 is too close to call. Its fate will probably not be decided until the afternoon of the debate which is to be held in camera in the Burlington Hotel, Dublin.

At present there is broad acceptance for the view of GAA President Joe McDonagh that the rule which prohibits members of the northern security forces from membership of the organisation must go now. Opposition to the view is largely confined to the six cross-border counties, but the ripples of dissent are spreading.

This is despite the findings of the Sunday Times exit poll, conducted during last Friday's referendum in the north, that 57 per cent of nationalist voters thought that the GAA should drop its ban and the fact that the nationalist Irish News last week called for abolition in an editorial on Rule 21.

Donegal, Cavan and Monaghan are expected to back their fellow Ulster counties but more on the basis of collegiality than conviction. Assuming they do and that Down - who backed a call for abolition three years ago - change their mind in their special convention on Thursday night, all 67 of the Ulster votes will be ranged against deletion.

In the other three provinces, whereas there is an overwhelming majority in favour of McDonagh's stance, there is the odd county which wishes to be influenced by the opinions of the northern counties. All told this may be sufficient to deny the motion for deletion the two thirds majority needed to ensure its success.

The alternative motion for suspension is still a little ambiguous. It isn't yet clear whether this motion - seen as a compromise - will be put first to the weekend's convention or whether it will need a weighted or a simple majority.

Worst-possible scenarios for the motion on deletion indicate that a two-thirds majority would be difficult to attain but so much has yet to be decided that it's impossible to rule out the figure being reached.

There are likely to be about 305 delegates present at the weekend (precise figures won't be known until registration is completed on Saturday). This means that around 102 votes against the proposal will suffice to strike it down. The voting strengths of the provinces are: Connacht, 44; Leinster, 94; Munster, 59; Ulster, 67. Approximately 40 overseas delegates are entitled to vote.

The position of Joe McDonagh will be central to the whole debate. He raised Rule 21 at last month's Annual Congress and in his presidential address outlined GAA policy on the ban.

"As a matter of policy we have previously declared `that in the context of an appropriate political settlement in which the national and cultural traditions of the people of all Ireland are equally recognised and respected, the concept of an exclusion rule will have no relevance for us'. I believe that time is now upon us . . ."

McDonagh is believed to be anxious not to identify the issue exclusively with himself and has kept a low public profile on the matter since congress. The question for many undecided delegates and even for those who are opposing deletion is the extent to which they can damage the presidency without damaging the association.

Given that there is superficial unanimity on the essential question of whether the rule should go and opposition has been stated in terms of the time not being right, it would appear that the presidential initiative faces being shot down on the matter of timing.

Indications from Croke Park seem to suggest that the compromise motion, formulated last week by the management committee, proposing suspension has been advanced in the hope that it might prove acceptable to one and all. The corollary of such a move would be that the GAA would please neither its own hardliners who would plainly accept suspension only as the lesser of two evils nor anyone else who would be astonished at the association's inability to make anything better than such a mealy-mouthed gesture a week after the vote of the whole island for a new beginning.