Maria Steen's campaign to get on the presidential ballot paper was boosted today when Aontú leader Peader Tóibín stated that she had received the backing from an 11th member of the Oireachtas.
However, the name of the Oireachtas member who has decided to back Ms Steen was not made public.
The barrister and family rights campaigner now has the support from 11 TDs or senators, but requires 20 to become a presidential nominee.
The Independent Ireland party, which has four Oireachtas members, has said it would give its support to a candidate if they received the backing of 16 members of the Dáil or Seanad.
It is understood Deputy Tóibín is currently engaged in talks with another TD who, if they agreed, would leave Ms Steen just four Oireachtas members short of a nomination.
In a post on social media, he said: "There is only a small gap to bridge, but time is running out."
The close of nominations for the presidency is midday on 24 September.
Ms Steen is also following a parallel route to get on the presidential ballot paper - seeking the nomination from four local authorities.
Leitrim county councillors will decide on Monday whether to back her following presentations from 13 prospective candidates.
Polling is scheduled for Friday, 24 October, with a result expected around 9pm the following day.
SF participation in Áras race a 'game-changer' - McDonald
It comes after Sinn Féin leader Mary Lou McDonald said the party's participation in the Presidential Election campaign will be a "game-changer".
It has been mulling over its approach to the race for Áras an Uachtaráin, with two options at its disposal - either run its own candidate or back Independent Catherine Connolly's campaign.
Speaking at the National Ploughing Championships in Co Offaly, Ms McDonald said that she knew the proposal she would be bringing to the party, but that it would not be made public until Saturday.
"I think Sinn Féin's participation will be a game-changer in this election. It'll be very much game on.
"The leadership will bring its decision, make it public on Saturday. We're going to be very active in this very important campaign."
Ms McDonald said the party had been talking to the Connolly campaign team.
"Have we been talking to Catherine's campaign? Yes, we've been talking to a lot of people including Catherine's campaign, that has been part and parcel of our deliberations as you can imagine," she said.
Watch: McDonald says Sinn Féin's participation a 'game-changer'
Ms Connolly said earlier this week that she would be delighted if Sinn Féin backed her candidacy.
She has the support of the Social Democrats, Labour, People Before Profit, Solidarity and some Independents.
Sinn Féin TD Pearse Doherty was in attendance at the Ploughing Championships on Tuesday, where he refused to be drawn on whether he would be the party's choice.
He said: "The party has been very clear on how we’re going to make this decision. We’ll make this decision on Saturday."
"I can tell you one thing about Sinn Féin, we are bursting with characters who are fit to run for the president and I’ve no doubt about it," he added.
A spokesperson for Ms Connolly said that she is open to competition in any election.
She said that Ms Connolly has not spoken to Ms McDonald in relation to the election and that she would be very happy to get an endorsement from Sinn Féin, but awaits the outcome of its process.
