A rush for advantage between Democratic Left and the Labour Party has begun as Democratic Left cleared the way at the weekend for final talks about a merger of the parties.
On Saturday, Democratic Left's executive approved the continuation of the talks - but only after approving 25 candidates for next year's local government elections.
The party also decided to hold European Parliament election selection conventions for the Dublin constituency and one other as soon as possible, and almost certainly before the merger talks conclude.
This move follows Labour Party suggestions that, as it has already selected candidates for the Dublin constituency (Ms Bernie Malone) and for Leinster (Mr Sean Butler), these contests cannot be reopened in the event of a merger. Democratic Left's response in selecting its own candidates before the merger would force a reopening of the issue, party activists believe.
Meanwhile, in the most difficult constituency for the merged party, Dublin North West, the Labour organisation has asked the party's organising committee to approve the holding of a selection convention within weeks. This is an attempt by supporters of Ms Roisin Shortall TD to give her the tactical advantage of being an already selected candidate before the merger brings her constituency rival - Democratic Left leader Mr Proinsias De Rossa - into the party.
Dublin North West has been reduced to a three-seat constituency since the last election and it appears certain that if both were to run, one would lose their seat.
Negotiating teams from the two parties will attempt to resolve such local problems in the coming weeks. They believe merger talks must be concluded before the end of the year to allow for selection conventions to be held before June's local and European elections.
The negotiating teams must also agree how to accommodate senior figures from both parties at leadership level. Democratic Left has demanded a "shared leadership" during the negotiations of recent weeks but has not spelt out what this means.
Sources in the party say it does not involve sharing the position of party leader. Mr Ruairi Quinn, as leader of the larger party, will be leader of the merged party.
It is likely Democratic Left will be given deputy leadership but it is unclear whether the party will hold the sole deputy leadership or will hold a second such post with existing Labour deputy leader, Mr Brendan Howlin.
The issue of how to share senior frontbench portfolios also remains to be resolved.
Figures in favour of the merger in both parties also hope to attract some Fine Gael deputies to the party. Sources say there are individuals in Fine Gael of a "social democratic" outlook who would be attracted to a new force. They say no approaches have been made to individual deputies at this stage.
Democratic Left's executive meeting on Saturday heard some vocal opposition to the idea of a merger but endorsed the motion to continue the discussions "with a view to bringing about a union of the two parties as a basis for the new political formation we envisage".
It says that "this union will be based on: (a) an agreed mission statement which will have as its objective the formation of a left-led government; (b) a shared leadership; and (c) an agreed programme and agreed priorities for political action and practice".
The motion also confirmed that the outcome of the discussions would be subject to the approval of a delegate conference.
Democratic Left's next such conference will take place in November. Labour has indicated it will hold a special conference almost immediately afterwards to formally approve the deal.