As many as 150 ministers could resign in protest over the new decision which will allow gay ministers to be ordained.
It is the first major Presbyterian church in the world to allow openly gay and lesbian ministers after its assembly in May. Since the assembly six ministers have already left.
Although the church has authorised gay clergy, it has been voted that a formal decision will not be made on allowing gay people to train as ministers until its theological commission reported in 2013.
The Rev Ian Watson, of the evangelical group Forward Together said: “I know of five who have actually left or will do so in the next few weeks and maybe one more for whom this is on the cards. I am not one of them.”
Others in the church confirmed ministers are planning to leave, but the numbers will be small, a major obstacle to these ministers is that resignation results in loss of home, income, and future pension payments.
It would also see affected congregations lose their church and its buildings.