Environment Minister John Gormley is expected to be formally unveiled as the new Green Party leader tomorrow evening.
The Dublin South East TD should be well ahead of the only other candidate in the race, former MEP Patricia McKenna, when votes are counted tomorrow afternoon.
The deadline for completed ballot papers from party members is 12 noon tomorrow and officials will begin counting afterwards. "There could also be a late surge by members personally handing in ballots," a party spokesman said.
Former leader Trevor Sargent stepped down as leader last month after party members overwhelmingly voted to enter government with Fianna Fail.
The Dublin North TD had made a pre-election vow not to lead his TDs into power with Taoiseach Bertie Ahern's party. Ms McKenna, who served as an MEP in Europe from 1994-2004, voted against entering government with Fianna Fail.
A joint programme for government was later endorsed by a 86 per cent majority at the special delegate conference in the Mansion House last month.
New Carlow/Kilkenny TD Mary White has already been re-elected unopposed as deputy leader of the party. Postal ballots were sent out to all members with voting rights earlier this month.
The party returned to the 30th Dail with a tally of six seats. Finance spokesman Dan Boyle was unsuccessful in Cork South Central.