Sinn Féin members in the Dublin South West constituency have been ordered to stop all meetings and suspend all political activity.
It is after its councillors nominated Paddy Holohan for the job of Mayor of South Dublin following his suspension from the party.
Sinn Féin's local branch members in the area were told of the decision in a letter - made public late last night - from Ken O'Connell, the party's political director south of the border.
It says "some recent political actions" in Dublin South West were viewed by the party's Ard Chomhairle "with deep concern" when it met last weekend.
The move follows the nomination of MMA fighter Paddy Holohan for the job of mayor of South Dublin late last month.
Councillor Holohan had been suspended from the party for comments he made on his podcast about then-Taoiseach Leo Varadkar's family ties in India suggesting they made him "separated from society" here.
The party's president Mary Lou McDonald called the remarks "beyond offensive" when they surfaced during the general election campaign.
But late last month it emerged Holohan's suspension was over when fellow councillors in South Dublin nominated for Mayor.
The letter makes it clear the ban on activity under its banner in the constituency includes meetings among its council group there.
Party officials now plan a full review of the area and will meet on Saturday in Dublin to to set terms of reference.
