It has described been described as "an historic rally" by a member of the Concerned Irish Citizens group with prominent speakers lined up. It is also expected there will be a large representation from the Quinn family attending.
In the statement this week, the Concerned Irish Citizens group invited everyone who wants "justice and fair play" for the Quinn family to attend the rally on Sunday.
"The very survival of our communities is at stake and your attendance is vital," said the statement, adding that public representatives have also declared an interest in attending.
"It is time for us all to unite and stand in solidarity with those who are being relentlessly and unjustly persecuted, to demand basic human rights and common decency and to send out a message loud and clear that we have had enough. We were promised transparency, accountability and fairness and we demand all three now."
The group denied reports that a collection will be taken up at the rally.