Bulgaria’s Prime Minister Boyko Borisov has instructed state-owned Bulgargaz and Bulgartransgaz to prepare to supply natural gas to Overgas in case Russia’s Gazprom Export halted deliveries to the Bulgarian-Russian joint stock company.

The instruction followed a meeting between Borisov and top Bulgarian energy officials urgently called over a letter from Gazprom Export suggesting the Russian company might halt gas deliveries to Overgas from the start of next year, bTV and Nova TV reported on Wednesday.

Bulgargaz, a wholly owned subsidiary of Bulgarian Energy Holding (BEH) and Overgas Inc, a company 50% owned by Gazprom Export, are Gazprom Export’s main partners on the Bulgarian market.

A halt in deliveries to Overgas could leave without gas about 200,000 households across Bulgaria.

Overdue debt of Overgas to Gazprom Export could be the reason for the letter, according to the Bulgarian TV outlets.

“The letter was sent to Overgas with a copy to Bulgartransgaz. The volumes ordered for delivery by Overgas from 1 January 2016 are marked with zeros, which means that Gazprom Export plans no deliveries to Overgas at the moment,” Nova TV quoted BEH CEO Jacklen Cohen as saying

Following the meeting with Borisov, Bulgargaz and Bulgartransgaz have said that if Overgas signs a deal with Bulgargaz to make up for the shortfall , the Bulgarian public gas supplier will provide the necessary volumes to avoid disruption of deliveries to households, bTV reported.

If Gazprom Export halts gas deliveries to Overgas, Bulgargaz will have to supply an additional 1.5 million cubic meters per day to consumers to fill the gap. The average daily consumption of natural gas in Bulgaria varies from 11 million cubic meters to 13 million cubic meters during cold winter days, according to BGNES.