Lobby groups may be prevented from the making presentations to the Constitutional Convention if they engage in excessive lobbying of its members, its chairman, Tom Arnold, has warned.

The Convention is set to examine a number of controversial issues, including same-sex marriage and amending the clause on the role of women in the home.

Groups such as Marriage Equality have already been in contact with politicians who are Convention members.

Speaking on RTE’s This Week programme following the first meeting of the Convention on Saturday, Mr Arnold said that ground rules for lobbying will be put in place and interest groups will be asked to comply with them.

He said he does not want citizen members of the convention to be subjected to undue pressure.

He said the balance needed to be struck between people expressing their views and the Convention listening to them.

He told the programme that he is very open to having views expressed, but a rule of “fairness” would apply.

Mr Arnold confirmed that all members of the Convention have accepted that their names and general areas of the country from which they come will be made public.

Taoiseach Enda Kenny promised that a referendum decision will be given on each recommendation four months after it is made.

Many of the 66 ordinary citizens drawn from the electoral register who are part of the Convention attended the meeting in Dublin Castle.

The others making up a total of 100 members consist of 29 members from the Oireachtas and four from the Northern Ireland assembly. Northern Ireland Unionist parties declined their invitation to take part.

By next February the convention will consider whether to recommend reducing the presidential term from 7 to 5 years and lowering the voting age to from 18 to 17 years.

They will also deal with a number of other issues including a review of the Dáil electoral system, giving Irish citizens resident outside the State the right to vote in Presidential elections, increasing the participation of women in politics and the removal of the offence of blasphemy from the Constitution.

Addressing the Convention, Mr Kenny said that these recommendations would not be shelved as had happened with other constitutional reviews.

He said each recommendation would get a decision on whether to hold a referendum and a timetable for any vote within four months of each recommendation.