GAY people will receive a formal apology from The Church of Scotland following its long "history of discrimination" under plans that signal another seismic softening of Kirk policy towards homosexuals.

In a landmark report, the influential Theological Forum will ask members of next month's General Assembly to atone for long-standing institutional prejudices against LGBT people by calling for an apology both "individually and corporately" on behalf of the church.

Another watershed proposal further paves the way towards greater acceptance of same-sex marriage by affirming that nominated ministers and deacons could be granted authority to preside over gay weddings provided there are protections for the "conscientious refusal" of clergy who do not wish to officiate such ceremonies.

The report by the Theological Forum, which counts former Moderator the Very Rev Professor Iain Torrance as its convener, said: “We recognise that as a Church we have often failed to recognise and protect the identity and Christian vocation of gay people and believe that the Church as a whole should acknowledge its faults.”

The Kirk has been debating same-sex relationships for decades but the appointment of the first openly gay minister Rev Scott Rennie in 2009 and last year's decision by the General Assembly to allow ministers to be in same-sex marriages has fuelled vigorous debate.

Addressing the new report, The Very Rev Dr John Chalmers, the Kirk's Principal Clerk, said: "In an argument over 20 years, some people have been hurt on both sides. Some have felt unheard, marginalised and denied.

"That why we think the recognition that some apologies all round are needed may help promote reconciliation and help us live with our differences where they exist.

"On the question of conducting same sex marriage, we are recommending our Legal Questions Committee now conducts a thorough appraisal of the legal situation.

"We need to be certain we will not lose our current protection under Equalities Law before we consider any change to Church law which could see ministers who wished to being permitted to conduct same sex marriages."

Last year the Scottish Episcopal Church became the first of any branch of the Anglican faith to make steps towards allowing its clergy to perform gay marriages and in February Church of England clergy appeared to signal support for gay marriage after they rejected a bishops’ report which said that only a man and woman could marry in church.

While the Kirk report stop short of a wholesale change of policy when it comes to gay marriage, it does appear to dilute the significance of gender roles within a marriage partnership and instead celebrate the concept of a loving relationship regardless of sexual persuasion.

The notion homosexuality is "intrinsically unnatural" - one of the most pronounced arguments made by its detractors - is countered within the report by highlighting how a sex-same relationship is "evidently" natural to the partners involved and that "homosexuality is more common in nature than may be realised".

And it acknowledges that as the Kirk has come to recognise the ordination of women - that the person who reads out the Eucharistic prayer over bread and wine represents "Christ in Christ's humanity" not in his gender - in a similar way, "we gradually learn that sexual difference is not theologically all determining as we may have thought".

The wide-ranging report explores the questions of human rights, sexuality and the history of marriage - first as a secular ceremony before becoming regulated by the church.

It notes that circa 1000 AD marriage was "modelled on the feudal vows of homage and fealty" which could see a union sealed by a feudal kiss on the mouth between the bridegroom and the bride's father.

The authors stress that marriage was made sacred in the 11th century but 're-secularised' during the time of the Reformation in which the clergy denied it was a sacrament and "reversed centuries of practice" by allowing ministers to marry.

The report states: "It is simply not the case that a single account of 'marriage' has been unchanged and constant throughout Christian history. And, similarly, it may be said that today also there is another wide scale of scrutiny of what counts 'as marriage' and what its benefits are."

A later section also argues: "We today cannot see the ocean choked with plastic bags and not think that somehow God is telling us how we are misusing the created world. And there are times when God speaks to us through the cries of God's people who long for inclusion and dignity".

Describing the report - which is entitled 'An Approach to the Theology of Same-Sex Marriage' - Scotland's first openly gay minister Rev Scott M Rennie said it was "far-reaching, thorough and impressive".

He said: "It seems to me that the Forum is asking the church at large to recognise the faith of gay people in its midst, and to cherish their part in the life of the church. The request that the Kirk recognise its failure through the years to value, encourage, and support gay people in its pews, and to do better in the future - is one of the most positive and hopeful things I have read in a report to the General Assembly in many years.

"It recognises, at last, the diversity of people that make up the Church of Scotland, and Scotland at large. It says in its own theological language: you are valued; you are part of us; and we have to do better at including you - and being just in our treatment of you.

"With regard to marriage, the report recognises what we all already know: marriage is and always has been an evolving institution. Loving marriages, whether they are gay or straight, can make for a good and happy life. Christ’s love for us his people is reflected in loving relationships. Marriage is something to be celebrated.

"I look forward to the day when I am able to conduct weddings for all couples, gay or straight, in the name of God.’

The Very Rev Dr John Chalmers added that the concept of a "sole victor" in the theological debate over gay marriage was outdated and what was now being proposed was the idea of a "constrained difference".

"This is saying that within limits we can make space for more than one approach among our ministers and congregations," he said.

"It is closely similar to what the Archbishop of Canterbury calls 'mutual flourishing'."

He added: "That is why I regard this as a centrist report, aimed at encouraging mutual flourishing.

"When mutual flourishing is what you aim for, then you try to heal where you can.

The General Assembly of The Church of Scotland will sit next month on The Mound in Edinburgh.