"We pay EUR 167 000 in forfeiture every day for these pieces of iron in Belene. Every time I think a ten days' payment will be sufficient to restore the Great Basilica [in Pliska], my heart is torn apart."

National History Museum head Bozhidar Dimitrov commenting on Bulgarian-Russian relations and an arbitration ruling under which Bulgaria is to pay for equipment produced by a Russian company for the abandoned Belene nuclear power plant project.

The Great Basilica was built between 865 and 870 in Bulgaria's first capital Pliska, as the country was undergoing a converstion to Christianity.

Repair works were announced in 2015. The activities in Pliska, however, have sparked controversy, with some historians questioning the methods of building "from scratch" by using large blocks that, some say, give buildings a "new" look.