Congregations are facing an insurance timebomb if they fail to properly protect deteriorating church buildings.

The general trustees of the Kirk told the final day of the General Assembly of the Church of Scotland yesterday that congregations must have assets revalued. It could add many thousands to budgets.

Some congregations have been shocked as premiums increase by up to 500%.

Increasing numbers of churches require repairs, with suggestions that more churches and associated buildings should be sold to cover costs.

Churches are exposed to losing hundreds of thousands of pounds from their value should a policy need used.

There was a call for grant aid to be provided by the Scottish Government.

The Rev Gordon Savage, of Maxwelltown West, Dumfries, called for greater flexibility and the investigation of alternative methods including "self-insurance" and backing from Holyrood for historic church buildings. He said: "Some premiums have gone up by 400-500% because of severe under-insurance in the past."

He added that, for many rural congregations, insurance payments were as much as 15% of their annual budget and in his area 117 properties were having to be revalued.

The exchequer south of the border gave English churches grant aid as they were considered important buildings. "I believe an approach should be made to the Scottish Parliament," he added.

Findlay Turner, chairman of the board of general trustees, said self-insurance was tantamount to no insurance and no church should contemplate it.

He said: "The fact is that many, if not most, congregations have not done what they ought to over a long period."

Another stance came from the Rev Anna Rodwell, of Oxnam, Jedburgh. She said her congregation was "staggered" by new bills but that, if rebuilding was necessary, a more simple structure would be preferred. Last year, the assembly directed every congregation's financial board to conduct a revaluation at least once in 10 years.

The end to the assembly was marked by traditional events including the ecclesiastical address by the Moderator, the Right Rev David Lunan.