Reverend Ian Watson, of Kirkmuirhill Church in Lanark, could become the only minister in Scotland to leave the Kirk over the issue of openly gay ordination, take the majority of members of the congregation and also retain the church building.
So far in all cases of ministers leaving with significant numbers of congregation members, they have been unable to lay claim to buildings the Kirk keeps in trust, as was the case with the worshippers who left St George's Tron in Glasgow to be based in nearby prayer halls.
But it is understood the Kirkmuirhill Church title deeds - relating to previous governance under the old United Presbyterian Church of Scotland which united with the Church of Scotland in 1929 - have a clause that says if two-thirds of the congregation agree to move to a separate denomination, they are able to retain the church.
The landmark case is reaching a critical juncture as the congregation's 280 members are asked whether they want to leave the Church in a consultation due to end on December 11.Although the Kirk insists it owns the buildings, the breakaway group's lawyers would be expected to use the deeds and the two-thirds majority in their legal argument.
The case may prompt any congregations considering leaving the Church to re-examine their deeds.
Separately, a Lanark presbytery member said Mr Watson's position - effectively collecting a Kirk salary while canvassing parish members to quit - is untenable.
Mr Watson declined to comment yesterday, but a source connected to the Lanark church said the minister's position was no different than if he was serving notice in any other position.
He was open about his plans to go the Free Kirk and he is also carrying the pastoral needs of the parish, the source said.
A further twist came when the Presbytery of Lanark took the step at a meeting on Tuesday night of giving Mr Watson an ultimatum to leave the Church by Easter - a date originally set as January 15 but which was put back by the presbytery after debate on the night.
Rev Bryan Kerr, depute presbytery clerk at Lanark, said it had agreed to "give the minister and those members of the kirk session who wish to leave the deadline of no later than Easter Day to give written notice of their resignation of membership of the Church".
He said the presbytery was aware members of the Kirkmuirhill kirk session "are presently seeking legal opinion from outwith the Church of Scotland" over buildings' ownership, adding: "It is the clear view of the presbytery that the buildings remain in trust for use of the Church of Scotland congregation.
Although the UP Church was the third largest Presbyterian church in Scotland in the 19th century, it is thought this Lanarkshire case could potentially affect up to just 10% or around a handful of deeds connected to the UP Church's original estate, who may have no desire to leave the Kirk anyway.
The Kirk said no final decisions have been made over moves towards greater acceptance of openly gay clergy in a debate sparked by Rev Scott Rennie, who is in a Civil Partnership, taking up a role at an Aberdeen church in 2009.