One of the arguments used by those who have insisted on maintaining the current definition of marriage as being between a man and a woman has been that redefining marriage would suddenly mean that anyone who thinks that a child needs a mother and a father would suddenly be defined as a bigot.

Once the state says that marriage is no longer about ensuring that as many children as possible are raised by their biological mother and father, but about validating adult sexual relationships, then society will view the former attitude as simple prejudice.

It seems to be happening in Britain already, to judge by comments made by Nick Herbert, Government minister for policing and justice, who said that opposition to same-sex marriage is “not acceptable”.

Mr Herbert, a Conservative, told the London Evening Standard that he was “getting rather fed up with people metaphorically jabbing a finger into my chest and saying I should put up with a civil partnership.

Mr Herbert, who is gay and in a civil partnership, said: “How would they like it if I jabbed a finger into their chests and said they should put up with a civil partnership instead of their marriage?

“In my view it’s not acceptable to say to a group in society, ‘You should put up with something that is a second-order institution to something that everybody else is entitled to, because we say so’.”

The issue has divided the Conservative Party to such an extent that Prime Minister David Cameron has been forced to guarantee all his MPs, whether backbenchers or ministers, a free vote on the issue.

However Deputy Prime Minister Nick Clegg has said that his Liberal Democrat MPs will not be given a free vote, and will be expected to vote for the Government’s proposal.

The Secretary of State for Northern Ireland, Owen Paterson, says he won’t support gay marriage and a number of other ministers, including the Secretary of Defence Philip Hammond, have expressed reservations.

It is also understood that the controversy could impact adversely on donations to the Conservative Party. According to the Mail on Sunday three of the party’s biggest givers are thinking of cutting back their support over the plans to redefine marriage.

It suggests that there is a live debate on the issue in the UK, and that many are uneasy about the prospect of redefining an institution which for thousands of years has provided security and stability to the vast majority of children.

All of this debate, Mr Herbert says, is “not acceptable”.

Perhaps someone should tell him that it is “not acceptable” to shut down debate over a proposal that is profoundly radical.