The opposition GERB party of popular Sofia mayor Boyko Borisov, backed by environmentalists, have raised alarm over of large-scale land swaps, one of the most widely spread corruption schemes in Bulgaria.

In January, Bulgaria's parliament imposed a ban on all land swaps under pressure from dozens of environmental groups.

Nearly fifty deals, in which state-owned land was allegedly swapped for private plots in less attractive or lower-priced parts of the country, have been greenlighted by the State Forest Agency at the beginning of the year before the ban on them was promulgated, GERB representatives said on Thursday.

GERB experts presented a list of the land swaps, the majority of which concern plots along the Black Sea coast and in the mountain resorts. The state has set a price ranging between BGN 0,24 to BGN 27 per square meter, way down below the market price of EUR 100 per square meter.

The party of Sofia mayor, which is tipped to win the next general elections in the country, suspects state administration officials had close links with politicians whose vested interests the land swaps served.