Greece’s Orthodox Church will resist a push by its Russian co-religionists for talks to stop Ukraine’s Church breaking away from Moscow’s orbit, Greek church officials said on Tuesday, deepening a rift within the global Orthodox Christian community.

The Ukrainian Orthodox Church wants to become fully self-governing, or autocephalous, and has sought the support of the Ecumenical Patriarch of Constantinople, the spiritual leader of the world’s roughly 250 million Orthodox Christians.

Seeking to prevent Ukraine’s separation, the head of the Russian Orthodox Church, Patriarch Kirill, has written to all the self-governing Orthodox Churches calling for talks about the situation in Ukraine.

“The Greek Church examined the letter and will respond shortly,” an official of the Greek Church told Reuters, requesting anonymity.

Asked what the response would contain, the source said: “It will not be in favor of convening the Orthodox Churches to discuss the issue. It will also underline the need for unity among Orthodox churches.”

The Bulgarian Orthodox Church also turned down the Russian call last week.

The row over Ukraine is threatening a major rupture in Orthodoxy, which wields significant influence in certain countries where it is the dominant religion.

The Russian Church last month declared it would no longer take part in structures chaired by the Ecumenical Patriarchate of Constantinople, which is expected to decide soon on whether it backs the independence call of the Kyiv Church.

“The estimate is that the Ecumenical Patriarchate will examine the issue of autocephaly of Ukraine’s church in the coming months, maybe by the end of October,” the Greek official said.

“After that the Greek Church will decide its stance on the issue”.

The Ecumenical Patriarch, currently Bartholomew, does not wield the power enjoyed by the Pope in the Roman Catholic Church but is traditionally regarded as the ‘first among equals’ among the patriarchs of the self-governing Orthodox churches.

The Ecumenical Patriarch resides in the Turkish city of Istanbul, the former Constantinople, which has remained the historic seat of Orthodoxy despite its fall to the Muslim Turks in 1453.