FORMER moderators and one of the most controversial figures in the modern church took to the floor over the question of independence in a groundbreaking debate at the General Assembly.

The Church of Scotland held a special referendum discussion during the week of its annual gathering in Edinburgh, although no vote was taken on the day.

The Kirk, which has 400,000 members, has a neutral stance on independence but passionate opinions were offered during the hour-long event that attracted 700 people.

Labour MP and shadow foreign secretary Douglas Alexander set out the case for retaining the union while Rev Doug Gay, principal of Trinity College, Glasgow University, argued for independence.

Former moderators the Very Rev John Cairns and Very Rev Lorna Hood raised concerns over national identity and the government's approach to religion in the White Paper.

Rev Scott Rennie, the openly gay minister whose appointment in 2009 to an Aberdeen church sparked the Kirk's gay clergy debate, backed the union, while another said independence was "not Braveheart freedom, it's about self-determination".

Renfrewshire MP Mr Alexander, whose father and grandfather were Kirk ministers, said: "Whether to remain part of the UK or walk away from our neighbours is an individual choice for each voter in Scotland but it is also a decision about the nation we are and the better nation we want to become.

"Given the degree of integration between the Scottish and UK economies, it is inevitable and appropriate that serious economic questions will continue to be asked in the months ahead."

He said devolution had "eliminated Scotland's democratic deficit, returning its distinctive institutions to the direct accountability of its people".

"Given that historic change it cannot be argued seriously any longer that Scotland's culture, its distinctive institutions, or its nationhood are today threatened by the partnership that is the United Kingdom.

"The referendum, in fact, is an opportunity to reaffirm the common endeavour of sharing risks, resources and rewards across these islands and to uphold the ethic and the practice of neighbourliness — being our brother and sister's keeper."

He said in summing up: "The way of changing Scotland is not by changing the constitution, it's by changing minds and hearts."

Mr Gay, a leading Scottish theologian, said: "I want to vote Yes and leave the parliamentary union because I do not believe the UK as it stands is capable of making the journey of reform it so badly needs to make.

"It cannot make the cultural journey of properly recognising and respecting Scottish, Welsh and Irish cultures.

"I'm not imagining that there's going to be a utopia but there is a problem. I don't think the ­democratic deficit has been overcome."

He added: "This will not fix everything overnight. It is a historic opportunity for us to change something for the better and I hope we take it."

However, former moderator the Very Rev Lorna Hood criticised the Scottish Government's White Paper. She said: "I would like some sort of assurance about the future of not only our national church but of all religious groups in Scotland. If we do have a Yes vote and if we have a written constitution surely we need more of an assurance than one line in a 600-page document."

Mr Rennie, whose case is at the centre of the debate on gay clergy which is due at the assembly today, said: "There's a sense that we are living in an increasingly unequal world. There's a definite need for constitutional reform."

But he added: "I don't think an independent Scotland can really deliver the quality in social equality that we really want to see.

"I think independence is an illusion of social change.

"We change nothing by drawing a boundary."