The Mormon Church is threatening to excommunicate a long-time member who legally married his long-term male partner in Toronto, Canada last year.

Buckley Jeppson, 57, married Mike Kessler in 2004, but says senior church official recently told him his life is incompatible with the doctrine of The Church of Jesus Christ of Latter-day Saints and that a disciplinary council would address the matter.

If Mr Jeppson, who lives with Mr Kessler in Washington DC, is excommunicated, it would be the first time a Mormon in a legal, same-sex marriage was punished by the church, according to a statement the gay advocacy group for Mormons.

Mr Jeppson said a senior leader of a group of Mormon congregations in the Washington area have been pressing him to resign his church membership for the past five months if he wanted to avoid further disciplinary action. Mr Jeppson told the Associated Press that is something he is not willing to do because he would never choose to deny his heritage and his faith.

A church spokeswoman said it is the policy of the Mormon church to allow only those in heterosexual marriages to be members.