Fianna Fáil will finally choose a candidate to run in next month's Kildare North by-election tonight, following weeks of delay.
A tight contest is expected in the convention vote, to be held in the Glenroyal Hotel in Maynooth, between Cllr Michael Fitzpatrick and Ms Áine Brady.
The other candidates in the race are Cllr Liam Doyle from Clane, Mr Anthony Creevy from Naas, and Cllr Willie Callaghan, who is also from Naas.
The Fianna Fáil gathering, which is expected to be attended by 300 people, will be chaired by the Minister for Finance, Mr Cowen.
Cllr Fitzpatrick, who ran the constituency operation of the former minister for finance, Mr Charlie McCreevy, topped the poll in the Clane ward with 1,652 votes in the 2004 local election.
Ms Brady, the sister of the Government Chief Whip, Mr Tom Kitt, and Galway East TD Mr Michael Kitt, lives in Clane, and teaches in Celbridge.
Her candidature has been quietly but strongly backed by Fianna Fáil's headquarters, but the majority of the 60 delegates may divide in Mr Fitzpatrick's favour.
Though Cllr Fitzpatrick did well in the local elections, he was followed closely home by his fellow convention candidate, Cllr Doyle, who received 1,435 votes.
Fianna Fáil has had considerable difficulty selecting a candidate since Mr Charlie McCreevy jnr declined to run at this time. Though it is not yet fully clear if he wants to run in the next general election, Mr McCreevy jnr ignored encouragements to run from Fianna Fáil headquarters.
Cllr Paul Kelly, who ran alongside Mr McCreevy snr in the 2002 general election, decided not to contest the by-election late last year.
The decision of the Taoiseach, Mr Ahern, to put Mr Cowen in charge of the party's campaign in the rapidly growing constituency is highly significant.
Many McCreevy loyalists in the party's local organisation are still annoyed that their political favourite was removed against his will from the Department of Finance.
The other candidates in the race are Fine Gael's Mr Darren Scully, a member of Naas Urban District Council, Progressive Democrat Senator Kate Walsh, the Green Party's Councillor J.J. Power, who sits on Kildare County Council for the Naas electoral ward, and the Independent Leixlip-based councillor, Ms Catherine Murphy.