Bulgaria has imposed punitive taxes on Russian-owned oil and gas operations, in an effort to make them less profitable and force them and their European buyers to look for other options, according to government officials.

Sofia on Friday introduced a Lv20 (€10) excise tax per megawatt-hour of transiting Russian gas, days after it hit the Russian-owned Lukoil refinery on its Black Sea shore with a 60 per cent tax on profits. The main goal of both measures was to squeeze the Russians out of the European market, officials said.

An EU and Nato member, Bulgaria has performed a drastic turnround since a pro-European government came into power in May. Up until very recently, the country was closely aligned with Moscow and had been reluctant to shake off its dependence on Russian hydrocarbons.