They will don wedding dresses for the march and hand in guidelines to the Government explaining why 100 people should be allowed at ceremonies and receptions.
Tanaiste Leo Varadkar said yesterday that couples should assume they can only have 50 guests next month.
Tara Fay, President of the Wedding International Professionals Association, says this has been very disappointing for couples:
"At the beginning of June when they were told that there was a possibility that they could have 100 guests for August, they sent out invitations in June for August weddings. You cannot just invite people overnight for weddings; that is not how it happened. It's not it's not like a little barbecue in your backyard where you suddenly ring people up the day before and go "Do you fancy joining us for our wedding tomorrow?" A wedding has to be planned well in advance."