Minister for the Environment John Gormley and former MEP Patricia McKenna are the only two candidates nominated to contest the vote for leader of the Green Party.
Mr Gormley helped negotiate the coalition arrangement with Fianna Fáil, while Ms McKenna opposed the deal.
Both were endorsed by 50 Green Party members, a requirement of party rules for the leadership contest.
As the sole candidate for the position of deputy leader, Mary White TD for Carlow Kilkenny, has been deemed re-elected.
Former leader Trevor Sargent stepped down last month after his party members voted to enter Government with Fianna Fáil. The Dublin North TD had made a pre-election pledge not to lead his TDs into power with Taoiseach Bertie Ahern's party.
Some 1,000 Green Party members are eligible to vote in the election and postal ballots will be sent out on Monday.
Ballots must be returned by noon on Tuesday, July 17th and counted. The result will be known that evening.