"In Crimea and eastern Ukraine, we've already effectively returned to the catacombs," said Fr. Ihor Yatsiv, the Church's Kiev-based spokesman.
"It's a sad paradox that history is being repeated just as we commemorate our liberation. But after a couple of decades of freedom, we again look set to lose our freedom," he told Catholic News Service Dec. 18.
The priest spoke as Ukrainian Catholic communities in Russian-occupied Crimea approached a Jan. 1 deadline for re-registering under Russian law. He said the Byzantine Ukrainian Catholic Church had no legal status in Russia and would therefore be unable, in practice, to register.
Yatsiv said Russian and separatist forces had not officially refused to register Ukrainian Catholic parishes, but had ensured it was impossible because of the lack of legal provisions. He added that there was no effective government in separatist-controlled eastern Ukraine, where rebel groups did not recognize Ukrainian Catholics and were "imposing whatever rules and regulations they choose."
Earlier in December, Archbishop Sviatoslav Shevchuk of Kiev-Halych told Austria's Kathpress news agency that Crimea's five Ukrainian Catholic parishes would find themselves "outside the law," along with the territory's Latin Catholic, Muslim and breakaway Orthodox communities.
"It's ironic we've just been celebrating the 25th anniversary of our legalization in the former Soviet Union — but our right to legal activity will soon be withdrawn in various parts of our country," Shevchuk said Dec. 12.
"There's clearly no religious liberty already in Crimea and the occupied territories of the east, and I hope the international community will deploy its resources to restoring freedoms in the affected areas," he said.
Ukrainian Catholics fled Crimea to escape arrests and property seizures after Russia annexed the region in March. Most church parishes have closed in Ukraine's war-torn Luhansk and Donetsk regions, where separatists declared an independent "New Russia" after staging local referendums last spring.
Ukraine's Catholic Caritas charity warned Dec. 11 of a "humanitarian catastrophe" this winter, with 490,000 people now registered as refugees, and 545,000 displaced abroad, mostly in Russia.
The Ukrainian Catholic Church makes up around a tenth of Ukraine's 46 million inhabitants. It was outlawed under Soviet rule from 1946 to 1989, when many clergy were imprisoned and most church properties seized by the state or transferred to Russian Orthodox possession.