Deputy Chris Green, a member of the States working party consulting on plans to replace current marriage laws with a new system of 'union civile', said the change would bring equality and legally recognise partnerships between couples without the religious connotations that the term 'marriage' brought.
Under the reform all couples, no matter what sexual orientation, could be joined together in 'union civile'.
However, the word 'marriage' would apply only to those having their union civile blessed by the Church and this is something that faced criticism from deputies and members of the public on social media.
Commentator Horace Camp said he was completely in favour of the concept of equality for all behind the proposals, but opposed to the idea that 'marriage' would be reserved for religious purposes only.
He warned 'equal marriage ends discrimination, union civile doesn't'.
'It is the idea that the term ''marriage'' is being ring-fenced for religious purposes,' he said.
'It is taking out marriage and giving it to religious groups, so they can have "union civile plus".'
Deputy Peter Sherbourne was among those who questioned why Guernsey was not moving towards full civil marriage, as in Ireland.
Deputy Green, however, has defended its work.
'As far as I'm aware there was a feeling that the definition of marriage was something which should be looked at from a States definition in a secular approach rather than religious approach'.
Equality charity Liberate's chairman Martin Gavet said the group was supportive of either the union civile or equal marriage options. 'It does not concern us so long as everyone is treated fairly and equally under the law,' he said.