Radio and TV stations have been told that - as part of balanced coverage - they must challenge false claims being made about marriage equality.
The Referendum Commission, which issues impartial facts, has already stated the outcome of next Friday's vote will have no effect on adoption, surrogacy or church weddings.
Anyone claiming otherwise, according to the Tanaiste, should face "robust questioning".
Joan Burton said that "if people make unsubstantiated allegations" that have nothing to do with the referendum, "programme people should be alert to question those kind of allegations when made".
