Sinn Féin figures say they were left with "no option" but to expel a sitting councillor, and suspend a second, following a lengthy internal probe by the party's top brass.
Sinn Féin President Gerry Adams was among a group of party bosses that this week sanctioned the expulsion of Cork councillor Kieran McCarthy, as well as the 12-month suspension of his council colleague Melissa Mullane.
The Irish Independent can confirm that a number of Sinn Féin members in the Cork East constituency will also be sanctioned following the internal review.
Several party sources said that sitting Cork East TD Sandra McLellan had aired serious concerns about the running of the constituency branch in recent weeks.
There had also been tensions between Ms McLellan and both councillors in question. Both Mr McCarthy and Ms Mullane had expressed their desire to contest the upcoming General Election, as had deputy McLellan.
The two politicians disciplined have 21 days to appeal their sanctions, but as of last night had not communicated to the party as to their intentions.
Several party figures who spoke to the Irish Independent confidentially said the charges against both councillors were serious. But sources refused to divulge the exact nature of the issues that led to the disciplinary action for fear it would "compromise due process".
Mr McCarthy, who is a Cobh-based councillor, last night claimed he has been "effectively stabbed in the back" by his party.
"After serving Sinn Féin for 34 years and making a number of personal sacrifices along the way, the party has effectively stabbed me in the back," he said on his Facebook page.
"What it has not done is to state the real reason why it wanted rid of me and Cllr Melissa Mullane, the two individuals who just happened to express an interest in contesting convention in Cork East in the coming election.
"No matter what happens from here on in, I will continue to work as hard as ever for those who supported and voted for me last year and for anyone who needs my help as a councillor.
"What happened this morning was a blatant attempt to override the democratic process and stifle the will of Sinn Fein membership in Cork East who clearly had lost the confidence of the sitting TD."
In relation to Mr McCarthy's claims, a senior party figure last night rejected suggestions that the membership had lost confidence in Ms McLellan.
The source said it is virtually unprecedented in recent times for the party to expel a councillor.
The sanctions were issued following a review of the constituency, which was overseen by Cork TD Jonathan O'Brien.
Neither Ms Mullane or Mr McCarthy responded to requests for comment.