Russia halted natural gas deliveries to Bulgaria in April after the government in Sofia refused to pay in rubles.
Bulgaria has been almost totally dependent on imports from Gazprom for most of its gas supply: the three billion cubic meter annual imports from Russia covered nearly 90 percent of Bulgaria's gas demand.
Since then, Bulgaria has been struggling to find alternative options like Azeri gas or LNG gas from the United States to cover its needs.
While large parts of the industry do not rely on gas, there are several big enterprises that are fully dependent on natural gas.
Experts fear that sharp price hikes or lack of supply would force them to limit production or stop work and add to the economic woes.
The head of the Bulgarian Industrial Capital Association Vassil Velev estimates that a shutdown of these enterprises would mean that some 250,000 workers will lose their jobs.
In Bulgaria, the poorest among the European Union's 27 members, surging energy costs are forcing families to cut extra spending ahead of the coming winter months to make sure there is enough money to buy food and medicines.
According to Eurostat, more than a quarter of the seven million Bulgarians can't afford to heat their homes - which is the highest number in the EU.
Having to choose between heating their homes and putting food on the table, many financially strapped households will be unable to keep their homes warm this winter and risk falling into energy poverty.
Statistics show that even middle-income households could struggle to pay their utility bills.
Scarcely insulated buildings, low incomes, and surging energy prices are the main causes of energy poverty.
In Sofia, where almost half a million households have central heating, the number of those who decided to switch to other heating options jumped after the announcement of a 40 percent price increase.
Across the country, nearly half of the households use firewood in winter as the cheapest and most accessible fuel, but the rising demand and the galloping inflation have driven prices up above last year's level.
Authorities are trying to lessen the financial burden on low-income households, mainly pensioners and the unemployed, by providing an energy allowance to buy wood for their stoves.
Other government-sponsored protective measures include export limits for wood-processing companies and regular deliveries of firewood for the domestic market.