Fianna Fáil has decided against issuing a gender diktat in Dún Laoghaire, paving the way for a three-person battle between former minister Mary Hanafin and councillors Cormac Devlin and Kate Feeney.
Senior Fianna Fáil sources last night described the decision as "carefully taken" given the threat of legal action made by Mr Devlin.
The frontrunner in next Monday's convention had sought legal advice amid growing speculation within the party that a diktat would be issued which would prevent him from running.
Even as late as Monday, senior figures with a direct role in candidate selection said the preference was for a sole female candidate strategy.
However, it emerged last night that the party had agreed against forcing the issue.
Mr Devlin is now likely to win the convention which takes place on Monday.
The party will then have to decide whether to add Ms Hanafin or Ms Feeney to the ticket, sources say. Ms Hanafin is seen as the favourite, but the decision will prove divisive.
A third potential female candidate, councillor Jennifer Cuffe, has moved constituency.