A demonstration will be held outside the Church of Scientology's National Affairs Office at Dublin's Merrion Square today.
The organisation expanded its operation in Ireland by opening a new church in Firhouse last month.
It was greeted by protests, with local TD Sean Crowe describing it as a "cult" which he would "not encourage people to get involved in".
Former Scientologist Pete Griffiths explained why they are holding the demonstration today.
He said: "There has been an injunction in place for the last three years preventing people from doing such things, so it is a celebratory demonstration.
"We intend it to be fun rather than confrontational and we just want people to know that Scientology organisations are not what they say they are."