Social Protection Minister Regina Doherty has said a decision to expel a member of Young Fine Gael from the party was "silly".
Jude Perry, the son of former Fine Gael minister of state John Perry, said his membership was cancelled because he supported an independent candidate.
His father is running as an independent in the general election.
The 21-year-old is from Sligo but currently studying in Washington, DC.
He posted a photo of a text message he said he received from the party on Wednesday.
He also said he received "no written notice, no proper reason or evidence provided and no fair hearing."
"Where is the professionalism and common decency. When we are trying to attract young people into politics, why have I been targeted?", he said on Twitter.
In the screenshot, the text reads: "I had information that you had campaigned/promoted an independent candidate which is a clear breach of Fine Gael rules.
"I passed that information onto headquarters and they made a decision to cease your membership."
On Wednesday, I was expelled from @FineGael by a text message. No written notice, no proper reason or evidence provided and no fair hearing.
Where is the professionalism and common decency. When we are trying to attract young people into politics, why have I been targeted? pic.twitter.com/YkReVgZfSV
— Jude Perry (@judeperry98) January 25, 2020
Minister Doherty told On The Record: "I think it's a terrible pity - Jude is a wonderful young man".
"I don't know where that decision came from, but it's a silly decision and Jude is very welcome back into our party".
She also said she would like to know who was responsible for the text message.
Earlier, Jude told Newstalk Breakfast he was surprised by the move.
"I'm currently in Washington, DC where I've been since January 9th before the election campaign began - and I will be until June.
"I haven't canvassed a single person or been actively involved in the campaign at all.
"That's why I found this news to be quite distressing, and being away from friends and family I found it to be deeply saddening also.
"This is a party that I've given the best part of my whole life too.
"My dad was a TD for Fine Gael for 19 years, and I was canvassing for the party from a very young age.
"More recently I was involved in the set up of the first branch in Northern Ireland - in Queen's University - I was appointed to the Northern Ireland engagement group by An Taoiseach, and I've been a member of the Sligo/Leitrim constituency executive for three years".
Asked if he had supported his father's campaign through Facebook, Jude said: "I've boosted a handful of posts from his account, but if you check my own private social media - both Facebook and Twitter - it will show very clear support for Fine Gael".
"I think there is due process - we don't live in China or Putin's Russia.
"I think that when an accusation is made against someone there should be a fair hearing - I've been given no fair hearing."
"I find it quite saddening and astonishing that Fine Gael are expecting me to disown my dad and choose party over family".
