The outcome of tonight's selection convention to choose Fianna Fáil's candidate for the Dún Laoghaire constituency could be much closer than has been predicted.

The race for the single slot on the ticket among the three high-profile candidates – former minister Mary Hanafin and local councillors Kate Feeney and Cormac Devlin – has attracted much media attention in recent months.

Over recent weeks the party’s national constituency commission (NCC) issued strict gender quota diktats in two Dublin constituencies, effectively barring male candidates from seeking the nomination.

There was speculation that a similar instruction would be issued for Dún Laoghaire. Private polling has shown that Ms Hanafin is considered the party’s best prospect of winning a seat in a constituency that is effectively a three-seater.

Ceann Comhairle Seán Barrett was elected to this four- seat constituency but he is entitled to be automatically re- elected to the Dáil.

Mr Devlin has recruited new members since 2012 and built up a strong support base in Dún Laoghaire. He threatened legal action against the party if the NCC, chaired by Cork North West TD Michael Moynihan, imposed a gender instruction that would prevent him from seeking a nomination. In the event the NCC issued an instruction that one candidate be chosen at tonight’s convention in Fitzpatrick Castle Hotel in Killiney.

There are about 190 delegates with voting rights in this predominantly middle class constituency.

The run-up has not been short of controversy. The date of the convention was brought forward by a few days. The upshot was that about 10 members recruited by Ms Feeney at the end of September last year are not eligible to vote as members must be registered for a year to be eligible to vote.

Long-serving activists

While Mr Devlin is seen as the front-runner, Ms Hanafin is likely to be supported by the majority of long-serving activists, who comprise a substantial number of the members.

Party sources said the outcome was not a foregone conclusion and that the final result would be determined by the transfers from the candidate who finishes third.

Ms Feeney, a former leader of Ógra Fianna Fáil, said she was disappointed by the unfortunate timing that had resulted in members she recruited being deemed not eligible. "If the convention were held the following day, they would be entitled to vote," she said. Nonetheless, there will be "an open race between the three of us".

“It is good that it is happening like this and I am happy that only one candidate is being selected. That is important. All three of us have said a one-candidate strategy is best. I would not like to see any additions to the ticket.”

She was referring to the possibility that Fianna Fáil headquarters in Mount Street might add Ms Hanafin’s name should she not come through at the convention.