The Government’s Civil Partnership Bill “effectively deprives all citizens of their right of conscientious objection” to civil unions, one of the country’s leading theologian has said.

Writing in the Irish Times, Dr Vincent Twomey, retired professor of moral theology at St Patrick’s College, Maynooth said that if the Bill becomes law, “people such as registrars, photographers or those responsible for parish halls, etc, will be forced to co-operate in acts they consider in good conscience to be morally wrong”.

He pointed out that a series of requests to the Minister for Justice Dermot Ahern (pictured), who is sponsoring the Bill, to include such a provision “including those from two Church of Ireland bishops” had been rejected.

Responding to calls by the Catholic bishops for a free vote in the Dáil on the issue, Dr Twomey said that members of the Oireachtas “have the primordial right as citizens and legislators to be free of the party whip and to follow their conscience”.

He added: “Conscience is the only bulwark against the totalitarian tendencies of all states.

“This finds recognition in the present German Basic Law (or constitution), which, to avoid a repetition of totalitarianism of the Nazi period, when the conscience of citizens was mercilessly crushed, insists those elected to parliament “ . . . shall be representatives of the whole people, not bound by orders or instructions, and responsible only to their conscience” (Art 38.1).

He pointed out that the German parliament, like Westminster, “allows a free vote on contentious moral issues”.

“By asking for a free vote in the Dáil on the proposed Bill, the Irish bishops in their recent statement did nothing less than reiterate this basic democratic principle,” he said.

Dr Twomey also referred to what he called a “tiny but very vocal minority” who were “outraged at the audacity of the bishops to express any opinion on this or, presumably, on any other matter.

Such people wanted the Church silenced, he said.

This, he pointed out, “would leave the way free for that tiny but vocal minority of secularists to impose their views on the whole of society, views that are repugnant to the sincere convictions of most citizens”.

The refusal to include a conscience clause in the Bill, Dr Twomey concluded, undermined “the primacy of conscience which is the bedrock of democracy”.

“The imposition of the party whip for the vote on this particular Bill (and on other similar Bills) is contrary to the right and duty of TDs and Senators to act as legislators in the full sense of the term, responsible to their conscience,” he said.