The first round in the Presidential election campaign went to Albert Reynolds yesterday when he had the satisfaction of observing John Hume's withdrawal from a race he had never formally entered. After four long weeks of careful consideration and consultation, the leader of the SDLP announced that he could not accept the great honour of becoming an agreed presidential candidate "at this time".

Mr Hume declared it was his duty "to stay with my colleagues in the SDLP and to continue to devote all our energies towards achieving a new and agreed Ireland based on a lasting settlement and a lasting peace".

The former leader of Fianna Fail, who had helped to engineer the first IRA ceasefire with Mr Hume in 1994, could afford a grim smile of satisfaction. He had seen his main challenger off. They might have worked hard together to secure a historic peace, but that didn't mean one man deferred to the other. When it came to political spoils, it was every man for himself.

For the past two months, Mr Reynolds has single-mindedly chased the nomination for President within Fianna Fail, in spite of a coldly hostile reaction from his party's leadership.

Both David Andrews and P.J. Mara publicly endorsed the nascent candidature of Mr Hume in August and drove their former party leader into a cold fury. But instead of bowing to this political bludgeoning, the former Taoiseach redoubled his canvassing efforts among members of the Fianna Fail Parliamentary Party. He would not stand aside and allow Mr Hume become an agreed candidate. If the SDLP leader wanted the job, he would have to fight him for it.

Now that Mr Hume has decided his duty lies in Northern Ireland, Bertie Ahern is faced with a difficult political situation. Having failed to secure Mr Hume as an agreed, all party candidate, he faces a greatly strengthened and rebellious Mr Reynolds within Fianna Fail.

And he has to contemplate the possibility of his partners in Government, the Progressive Democrats, offering support to an Opposition candidate. It happened before, in 1990, when Mary Robinson was elected. And history could repeat itself if Mr Reynolds and Des O'Malley have their way.

The former Taoiseach is now said to have garnered so many pledges of support within the Fianna Fail Parliamentary Party that Mr Ahern may not be able to prevent his formal nomination next week. As of now, his only official challenger for the position is Michael O'Kennedy, whose chances are not highly rated by the leadership.

Maire Geoghegan-Quinn appears to have written herself out of the screenplay, now that Mr Reynolds has hoovered up much of her support base. And while David Andrews would be only too willing to enter the fray, Mr Ahern is unlikely to sanction that development and risk the loss of a Dail seat to his minority Government. Last night, efforts were being made to draft Ray MacSharry, the former EU Commissioner, as an alternative candidate. But without any obvious success.

With Mr Reynolds steaming through the middle of the party, the Taoiseach had the thankless task of going on television and expressing "understanding" for John Hume's decision. In the obvious hope that Mr MacSharry might throw him a lifeline, Mr Ahern said nominations remained open until next Saturday. And bite-the-bullet time will be tomorrow week.

The situation was little different in Fine Gael, where the presidential election campaign has been on hold since mid-July.

A party spokesman observed that Mr Hume's decision was "perfectly understandable given the onerous demands which continue to be placed on him and the SDLP with the commencement of all-party talks in Belfast next week".

And now that an outsider is no longer interested in the position, the party's two candidates, Mary Banotti and Avril Doyle, will slug it out for the nomination at a parliamentary party meeting next week.

Dick Spring went on television to promise the nomination of a Labour Party candidate. And while he mentioned Michael D. Higgins in passing, party sources spoke darkly about a "surprise candidate" emerging within the next week.

There is, however, no question of the Labour Party supporting the candidature of David Norris, who was nominated by Tony Gregory, Brendan Ryan and Shane Ross. And it would seem that neither Dana nor Derek Nally are likely to receive sufficient official support to enter the race.

Now that Mr Hume has decided to make his bed in the North, the parties in the South will have to start counting the cost of a presidential campaign. It could cost Fianna Fail and Fine Gael up to £500,000 each, with lesser amounts being spent by the Labour Party and Democratic Left.

What would have been an open-and-shut presidential contest has, with the withdrawal of Mr Hume, become something of a political lottery. The Fianna Fail candidate - likely to be Mr Reynolds - must be regarded as the favourite, with about 40 per cent of the popular vote. But a strong Opposition transfer arrangement could replicate the 1990 upset, damage Mr Ahern's authority, and help to destabilise the present Government.