Fine Gael Deputy Leader Helen McEntee said she is supporting former minister Heather Humphreys in her bid to be the party's nomination to contest the Presidential Election.
The former TD and MEP Seán Kelly have both confirmed they will seek the nomination. Ms Humphreys is said to have the backing of around two thirds of the parliamentary party after putting her name forward.
Ms McEntee, the Minister for Education, said: "I’ve worked with her for many, many years and I believe she would make an excellent president representing people right across this country."
"I believe we are very fortunate to have two people of such high calibre willing to put their name forward in the first instance."
'I will be supporting Heather,' says McEntee
Earlier, speaking on Northern Sound radio, Ms Humphreys said she has "decided to go for it", having originally ruled herself out in May.
Asked why she changed her mind, Ms Humphreys said she had not wanted to stand against Mairead McGuinness, whom she described as a friend, but said all that had changed with Ms McGuinness' withdrawal from the race on health grounds.
Ms Humphreys said she was "a bit burnt out" last August when she announced she would not run in the general election.
She said she had been a cabinet minister at that point for ten years, and her tank was "probably running on empty".
However, she said she was doing well and her family was doing well, so she felt ready to run after "a good rest", adding she had "never felt as ready for a challenge".
Sources close to Ms Humphreys suggest she has the support of around half of the Fine Gael parliamentary party so far.
Under Fine Gael's rules, a candidate also needs the support of 25 councillors and five members of the Executive Council.
It is understood Ms Humphreys has spent the morning speaking to party councillors, TDs and Senators.
Ms Humphreys said she wants to be a president who represents "a modern and an outward looking Ireland with pride on the international stage".
She added it was important to reach out to communities, adding that she wanted to be a "president for all" of the country.
"We have a lot of divisiveness in our community at the minute," she said.
"I think we need to break down these preconceived notions, these perceptions, and we need to have conversations, and we need to bring people together."
She said the President was well placed to do this, as well as continuing the work of reaching out to communities in Northern Ireland.
Earlier, Fine Gael MEP Seán Kelly announced he will seek the Fine Gael nomination to contest the Presidential Election.
Mr Kelly said he believed the "time is right" to put himself forward, in light of the changed circumstances following Ms McGuinness’ decision to withdraw from the race, and after discussing it with family and supporters.
Speaking on RTÉ's Morning Ireland, Mr Kelly said his original decision to decide not to run was "the hardest decision" he ever made.
"Now that it [nominations] is open again, I am delighted and enthusiastic about the prospect of running for president, reflecting what many people have said to me," he said.
Mr Kelly said he underestimated the support he had at the grassroots level having been an MEP based in Europe.
"But in the last two to three weeks I have been at home and everywhere I went, people said to me 'Seán, we are very disappointed you didn't go forward'.
"That momentum has been growing so that has convinced me that I have a lot of support if I can get the nomination," he said.
Watch: 'I'm in it to win it' - Kelly to seek Fine Gael nomination
Mr Kelly said there is "huge potential in the job", which he described as "the highest honour in Ireland".
"If you look at what the last presidents have done, there is huge flexibility there. I would avail of that flexibility, to do an awful lot of work, to reflect what communities I am embedded in for many years would aspire to," he said.
Mr Kelly said he would be "very energetic" and would "bring the Áras to the people as much as people to the Áras".
He said he looks forward to the nomination process and any contest that might follow, adding that Fine Gael members have said they would like a contest.
"Contests are good for parties, they are good for democracy, I would welcome a contest and I hope I will be part of it," he said.
Nominations for the party’s presidential candidate reopened at midday on Tuesday and will close at midday on 2 September.
The decision came following a meeting of the Fine Gael Executive Council last night.
Tánaiste Simon Harris said the decision to reopen nominations will enable the party to have a candidate in place by mid-September.
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
Calls for FF to convene meeting over presidential candidate
Meanwhile, Fianna Fáil MEP Billy Kelleher has called for a meeting of the Fianna Fáil parliamentary party to be convened "urgently" to discuss running a candidate in the Presidential Election.
Mr Kelleher said Fianna Fáil should either run its own candidate or support a candidate that represents the party's values.
"In my opinion, Fianna Fáil, the largest party in the Dáil, the Seanad and in local government, should be actively involved in either running its own candidate or facilitating a candidate that represents our values and beliefs as a political movement," Mr Kelleher said.
He said a meeting should be convened soon as the next scheduled meeting in September would come "too late in the day".
He added that he has asked the chairperson of the parliamentary party, TD Brendan Smith, to convene the meeting to discuss "this most critical of issues".
Taoiseach Micheál Martin said on Sunday that his party would make its position on a candidate clear towards the end of the month, adding that Fianna Fáil would be making a "contribution" to the election.
Speaking on RTÉ's News at One, MEP Barry Andrews also said the Fianna Fáil parliamentary party needs to meet soon to discuss choosing a presidential election candidate.
"Clearly this is now a different prospect than had Mairead McGuinness run.
"I think, you know, the last time we had a nomination process for the presidency within Fianna Fáil was in 1997, where we nominated Mary McAleese, who went on to be one of the most successful presidents of Ireland. There is tried and tested methodology there for Fianna Fáil’s parliamentary party, to nominate them."
Barry Andrews also ruled out putting his own name forward as a candidate.
"I'm a member of the Conference of Committee Chairs in the European Parliament and also, I'm chairing the Development Committee at a time of massive, horrific cuts to overseas development aid," he said.
"I think that role that I have right now is really, really important, not to diminish the dignity of the office of President, but I think I have a very important job to do."
Mr Andrews said he did not have anyone in mind to go forward for the Presidency but added the criteria he would look for in a candidate would be somebody who understands the constitutional potential of the office and also the limits.
"We've heard names in circulation - some previous politicians, some retired politicians, some celebrities, some people who have contributed significantly to the civic life of the country," he said.
"But I'm confident that we will have a strategy to win the presidential election within the next couple of weeks."
