Mary Hanafin has responded to Mary Cowen's surprise attack on her in a Facebook post last week.
The wife of the former Taoiseach Brian Cowen had blasted Ms Hanafin, the former Education Minister, over remarks she made at the party's ard fheis.
Ms Cowen criticised her on a private Fianna Fail Facebook discussion page, which has almost 1,400 members, claiming that party leader Micheal Martin should "watch his back".
Ms Cowen wrote: "I see an article about Mary Hanifin (sic) stating that Fianna Fail members have called on her to influence party policy." She continued by saying that Ms Hanafin is "not elected yet and she is running the party".
Speaking to the Sunday Independent this weekend, Ms Hanafin described the remarks as "inappropriate" and said her loyalty to the Fianna Fail party and leader Michael Martin was in no doubt.
On the campaign trail in Foxrock yesterday morning, Ms Hanafin was initially reluctant to respond to the controversy, saying: "It wasn't an appropriate comment in the first instance and it wouldn't be appropriate for me to comment now."
However, when pressed on the matter, she said: "I could have walked away from the Fianna Fail party in the last local elections in 2014 with the way I was treated. [They said] 'We want you to run, we don't want you to run, we're pushing you off' and so on.
"And to be a longstanding member and loyal member of the party, I didn't [walk] because I am loyal and I am loyal to what the party stands for.
"I will question, I will criticise but I am a loyal member of the party and if I didn't walk away then, I certainly wouldn't walk away now," she said.
Ms Hanafin, who is on the Fianna Fail ticket in the Dun Laoghaire-Rathdown constituency, also responded to the accusations levelled at her, saying: "No, Michael Martin certainly [doesn't need to watch his back]. He has always been a good friend of mine.
"All over the years, we have worked well together and I always support the leader and I always have because in a political party you have to have a leader and you also then have to have people who will do their fair share of the work. I like to think when I was in government I did support the leaders of the government and worked very hard in my own ministries.
"[It] was true that people were coming up to me, saying they were looking forward to me coming back. But I am also inclined to say to people, 'Hang on a minute, we only have a three-seat constituency. It is difficult to win.'
"That's the big, big challenge and I keep saying it to people. But look, I'll certainly give it my best shot."
Asked if she would like to be leader of Fianna Fail, she said: "I went for it the last time in 2007 and I didn't get it and I don't think that opportunity is going to arise again. The first thing I have to do is get elected." But she added: "I certainly wouldn't rule it out."
Asked her feelings about the post, she said: "At this stage I let things go over my head. If I was starting off… but I take everything as it comes now. And I just get out there and do it.
"It's very easy for people all through an election campaign to get upset over a comment or a lack of invite or a missing poster but the election campaign is only a month long and the key is to meet as many people in person as possible and not to get distracted.
"I am very straight with where I am and what I am doing. I never comment on Facebook or any of those social media sites. Where I am good is face to face and out here meeting people and we will do more in one morning than any comment on a Facebook page."
Speaking about her late husband, she said: "You cannot prepare for it but you can get through it. Eamon died in 2003 but you only have one life and one love.
"Every time I go out to do something big I go in and have a quick look at his photograph, just a look, and I know everything is going to be okay. I don't believe he is gone forever."