IT is one church separated by a border - but this week Anglicans in the Church of England and in the Scottish Episcopal Church face falling out over the issue of same-sex marriages.

In the progressive corner is the Scottish Episcopal Church - in effect the Anglican church in Scotland - which is preparing to vote for clergy to be allowed to carry out same sex marriages. Meanwhile, its southern neighbours, the Church of England, is on the reactionary side, opposing any such move.

Members of the Scottish Episcopal Church will be asked if they back a change to canon law which currently states that marriage must be between a man and a woman, at the Church’s General Synod in Edinburgh on Friday.

The presiding bishop of the Church said if approved, it would be the latest step in a gradual progression towards making the Church more inclusive.

However Most Reverend David Chillingworth acknowledged it would create a schism with the Anglican Communion, an international family of churches which has the Church of England as its 'mother' church and the Archbishop of Canterbury as its spiritual head.

He said there was the possibility the Scottish Episcopal Church could even face sanctions from the Anglican Communion, similar to those imposed in January this year on a liberal US Anglican church after it permitted clergy to hold same-sex marriages. The US Episcopal Church was banned from representation on key bodies and from voting on certain issues for three years.

Chillingworth, who is Bishop of St Andrews, Dunkeld and Dunblane, said: "The Anglican Communion matters greatly to us and is also interwoven with our history - so to be out of step with the Anglican Communion is a really serious issue for us.

“But every church and every province of the Anglican Communion will one day have to address these issues of human sexuality. At the moment we may find ourselves somewhat out of step, but taking the long view I think others will address this issue.”

A revised canon law on marriage which takes out the reference to a man and a woman will be read for the first time at the Church's General Synod on Friday, before members of each house of the Synod – comprising of laity, clergy and bishops - vote by majority whether to back it.

If approved, the issue will be discussed over the next year, before a further vote takes place at the General Synod in 2017, which would require a two-thirds majority in each house to pass.

Chillingworth said a particular concern during the process was maintaining the unity of the church, adding: “As with every church there are people who don’t just disagree with this movement, they actually think it is wrong.

“In the case of something as fundamental as this, simply adding up the votes and declaring the winner doesn’t resolve the issue. You therefore have to work out how you are going to move forward as a church holding together while people believe these very different things.”

Tim Hopkins, director of the Equality Network, said it would be welcome if the Scottish Episcopal Church, which has 350 churches, allowed clergy to conduct same-sex marriages.

He said: “We would like to see all marriages treated the same, whether they are mixed sex or same sex, but it is a matter for the church to decide through its internal procedure."

Meanwhile the United Reformed Church, which has 50 churches in Scotland, will also vote on the issue of same sex marriages at its UK-wide General Assembly in July.

If a resolution is passed by two-thirds majority, it is expected Scottish clergy will then be able to opt to become a celebrant for same-sex marriages.