As the public debate on the forthcoming same-sex marriage referendum got under way in earnest last week, you could be forgiven for thinking that the two opposing sides consisted of the entire gay community and all political parties in favour of redefining marriage, with the only opposition coming from the Catholic Church and Catholic organisations such as the Iona Institute. The truth, however, is more complex as I know only too well as an agnostic gay man supporting a 'No' vote in May.

While I have little doubt that the most of the 'out' gay community are probably in favour of a 'Yes' vote, I know that I am far from a lone voice calling for rejection, but I am one of the few willing to raise their heads above the parapet. It is also well known that several politicians have reservations about this major legislative change, but are not prepared to speak out for fear of disobeying the party whip.

My objection to same-sex marriage is based on two core principles: that the State, its agencies and others charged with the welfare of children, should be able to favour a family unit that provides a mother and father and, secondly, I also believe that civil partnerships are a better way of legally recognising same-sex relationships and providing all the rights and entitlements that come with civil marriage and are a better way of expressing diversity.

Perhaps regrettably for those supporting its redefinition, you cannot discuss marriage in Ireland without discussing the family. Apart from the divorce limitations, the only time marriage is mentioned in the Constitution is in section 41, where the State commits itself to guarding marriage as the institution on which the family is based. Successive Attorneys General have told their government colleagues that same-sex marriage is in conflict with this.

Obviously other family units exist, and children can be raised successfully outside of traditional marriage and while all children should be protected equally in law, marriage should remain the cornerstone of the family unit and the best way of doing that is not to redefine it. The result of allowing same-sex couples to marry is that agencies that are entrusted with finding parents to adopt and foster children cannot legally favour families that can provide a mother and a father, which all evidence suggests is the best environment for children.

It is worth remembering that other countries such as Portugal have detached the introduction of same-sex marriage from the right of same-sex couples to adopt and while couples can marry, they do not have an equal ability to adopt. In Ireland the issues of the family and adoption rights should be resolved though the forthcoming Children & Family Relationships Bill, which was promised over a year ago. When this bill becomes law, children being raised by same-sex couples, single parents etc should have the same rights as all other children. Had this bill not been delayed it would have allowed a clearer debate on the dangers and any merits of redefining marriage.

Even if you see no merit in the State and its agencies being allowed to favour families that can provide a child with a mother and father, there are other reasons for voting 'No' in May's referendum. Five years ago, we introduced civil partnerships with the support of all parties in the Dail and these have proven to be very successful, allowing same-sex couples to have their relationships recognised in law. The take-up rate has shown that gay people clearly see civil partnerships as having merit in providing essential support on inheritance rights, next-of-kin status and employment-related benefits etc. Almost all areas where civil partnerships differ from civil marriage are connected with the raising of children and any deficiencies will be removed by the Children & Family Relationships Bill. Consequently it upsets me when those promoting same-sex marriage try to portray civil partnerships as a "second class marriage". That is most certainly not how I and most people that I know view them.

Where civil partnerships do differ from civil marriages is that partnerships are dissolved rather than forcing same- sex couples to go through the more difficult and sometimes expensive divorce process and adultery is not considered grounds for dissolving a civil partnership, while it is for a divorce in a marriage. This difference is because civil partnerships are not consummated in the way that marriages are, and unconsummated marriages can also be dissolved.

If same-sex couples wish to change civil partnerships, allowing adultery to be seen as legal grounds for ending the union and wish to force all couples to go through the divorce process in the name of 'equality' then we should have that debate, rather than redefining marriage, an institution which was established to support children and which does not reflect the reality of most same-sex relationships.

Personally I believe that civil partnerships are a better way of reflecting the reality of most same-sex unions and the idea that a civil marriage 'one size fits all' method of legally recognising all unions fails to address the fact that the relationship that a man forms with another man is intrinsically different from the relationship that a man forms with a woman. This difference is as fundamental as a man and woman are themselves different.

In Ireland, we are very lucky that the people are being given the right to decide on whether marriage should be protected as it currently is, or be redefined at the behest of a tiny but vocal minority. The small number of countries that have legalised same-sex marriage have done so without a vote and sometimes against public opinion, causing a great deal of resentment.

As a gay man I can think of many better ways of spending the €20m that this referendum will cost, to benefit the gay community and wider society. This referendum is unnecessary and should be rejected in order to keep the unique position of mothers and fathers special and to legally recognise the diversity of same sex relationships.

Sunday Independent