Independent junior minister Michael Healy Rae has nominated barrister Maria Steen for the presidency.
Ms Steen has been lobbying Oireachtas members to support her nomination, with Áontú leader Peadar Tóibín saying recently that half of the required 20 nominations had been secured.
Mr Tóibín said on Friday that Mr Healy Rae’s support brought the figure to 12, with two more Oireachtas members in discussions.
Alongside Independent Ireland’s four TDs, that would bring Ms Steen to 18. The party has said it will meet with the barrister if she secures 16 nominations.
In a statement, Mr Healy Rae, who previously backed Fine Gael candidate Heather Humphreys, said: “In 2011, I was approached by Sinn Féin to sign the nomination papers for Martin McGuinness.
“At the time, I made it very clear publicly that while I was prepared to sign to allow him the opportunity to go before the people, I would not be voting for him. I believed then, and still believe now, that democracy is best served when candidates who are serious and committed are not denied their place on the ballot.
“Today, I have decided to sign the nomination papers for Maria Steen. In the same spirit of fairness and respect for the democratic process, I will be giving her the opportunity to contest the election.
Michael Healy-Rae arriving at Leinster House ahead of the Summer Break. Picture: Sam Boal/Collins Photos
“However, I want to be absolutely clear: my support in this election is firmly with Heather Humphreys. I believe she is the right person to be the next President of Ireland and I am 100pc backing her campaign.
“Signing a nomination paper is not a signal of electoral support, it is simply ensuring that the people of Ireland are given a fair and full choice when they go to the polls. That is the foundation of democracy, and it is something I will always stand by.”
Ms Steen has been described as a conservative campaigner. A barrister by profession, she also holds a degree in architecture.
She has five children, ranging in age from three to 18. She has educated them at home and also holds a degree in Montessori teaching, she wrote in the Irish Catholic this week.
Ms Steen is a member of the Catholic advocacy group the Iona Institute and previously represented the body during referendum debates.
This included the 2015 referendum on marriage equality, during which she campaigned for a no vote. The referendum passed with 62% support.