Top executives from RTE, TV3 and Newstalk will today appear before an Oireachtas Joint Committee.
It is looking at the way in which information is given to the public during referendum campaigns.
The Independent Broadcasters of Ireland and the Broadcasting Commission of Ireland will also appear before the Committee.
It is examining the current procedures which determine the amount of on-air time given to both sides in the lead up to a referendum.
The Committee is drawing up a report, which will be presented to both Houses of the Oireachtas and the Government.