Lord Mackay argued this week for the law to protect freedom of conscience during a debate on the Equality Bill in the House of Lords.

The former Lord Chancellor said respecting conscience was not merely a matter of human rights but also of “prudence”.

He proposed an amendment to the Equality Bill, currently in the committee stage, that would exempt people from having to provide goods or services on occasions where doing so was in conflict with their conscience.

He said: “Over the many years during which I have been involved in the law and the political process, people have often grumbled to me about aspects of our legal system.

“Until very recently I have always responded that in Britain, while there are undoubtedly matters about which people could be legitimately anxious, one could always be assured that the law would not require you to violate your conscience.

“In recent years, however, and certainly since 2006, this has been brought into question.”

Giving the example of a Christian printer, Lord Mackay said that current equality legislation and the new Bill put them in a “very difficult position” if they were approached by a gay rights organisation that was asking them to print material promoting same-sex sexual relations.

He said that a gay printer would find himself in a similar position if he were approached by a Christian theologian who wanted him to print material calling same-sex sexual practice a sin.

He pointed to the example of doctors who are allowed to refuse to perform abortions on the grounds of conscientious objection.

“I welcome this Bill very much and certainly hope that it will, suitably improved, reach the statute book in good time,” said Lord Mackay.

“Yet I certainly think it right that it should be improved in this respect, by allowing individual conscience when it comes into play as a genuine conscientious conviction.

“It is possible to have lots of things that are not genuine, but I am talking of a genuine conscientious objection which should be allowed.”

The Bishop of Chichester, the Rt Rev John Hind, warned the Government against forcing people to restrict their religious beliefs to the private sphere.

He said: “The attempt to privatise belief, whether philosophical or religious, is a profoundly dangerous tendency and one that we need to address as we consider not only this but later amendments.”