The CEO of Russian natural gas giant Gazprom, Alexei Miller, is arriving in Bulgarian capital Sofia on Thursday to confer with the country's prime minister.

The government has released no information about the issues, which will be on the agenda.

Alexei Miller and Bulgaria's Prime minister Plamen Oresharski will make statements for the press after the meeting at the cabinet headquarters, but journalists may not be allowed to ask questions, according to media reports.

A year ago the previous center-right government of Boyko Borisov signed signed with Russian state-owned energy giant Gazprom the final investment decision for the construction of the South Stream gas transit pipeline.

The South Stream agreement was signed in the Bulgarian capital Sofia on November 15, 2012 by former Bulgarian Prime Minister Boyko Borisov and Gazprom CEO Alexei Miller, in addition to another agreement for the Russian natural gas supplies for Bulgaria, which stipulates a 20% discount as of January 1, 2013.

The South Stream pipeline is intended to transport up to 63 billion cubic meters of natural gas to central and southern Europe, diversifying Russian gas routes away from transit countries such as Ukraine.

The pipes will go from Russia to Bulgaria via the Black Sea; in Bulgaria it will split in two – with the northern leg going through Serbia, Croatia, Hungary, and Slovenia to Austria and Northern Italy, and the southern leg going through Greece to Southern Italy.

The Black Sea underwater section of South Stream between Russia and Bulgaria will be 900 km long, and will be constructed at a maximum depth of 2 km. In order to service the supplies for South Stream, Russia will expand its own gas transit network by building additional 2 446 km of pipelines with 10 compressor stations with a total capacity of 1473 MW, a project to be called "South Corridor" and to be completed in two stages by 2019.

The pipeline's core shareholders include Gazprom with 50%, Italy's Eni with 20% and Germany's Wintershall Holding and France's EDF with 15% each. Gazprom has already established national joint ventures with companies from Austria, Bulgaria, Croatia, Slovenia, Greece, Hungary and Serbia to manage the onshore section of the South Stream pipeline.

The opposition right-wing Democrats for Strong Bulgaria (DSB) party recently slammed the South Stream gas pipeline project as the "second huge corruption-ridden project of the Bulgarian Socialist Party (BSP), the Kremlin and the energy mafia."

To illustrate their point, DSB members pointed out that Bulgaria was not going to receive any money at all for 15 years in a row and all revenues generated by the gas pipeline during the period would go to Russian energy giant Gazprom.