The Lawyers Against the Amendment group has been criticised by the Pro-Life Movement, which claimed it was being "provocative and misleading".
The lawyers' group had described the process for the referendum as undemocratic because it took the power from the Oireachtas to amend the legislation in the normal way.
A spokeswoman for the Pro-Life Movement said the criticism was extraordinary. "What could be more democratic than a national referendum where every single citizen can vote on a piece of legislation?" she said.
"In this case, the issue is one that has resulted from a controversial judgement on abortion that has caused popular agitation over the past 10 years. And what could be more democratic than to allow the people to vote for a solution to that issue?"