Bulgaria expelled 70 Russian diplomats on June 28 – the biggest ever number in the history of the two countries’ relations, Prime Minister Kiril Petkov said.

The move by Petkov, who resigned a day earlier, is unprecedented for the country, until recently believed to be one of Russia’s most loyal allies in the EU.

The Foreign Affairs Ministry has informed the Russian ambassador to the country, Eleonora Mitrofanova, that the 70 diplomats and their families must leave the country by the end of July 3.

“We are expelling 70 Russian diplomats. Anyone who is working for foreign interests will be urged to return to the country where he came from,” Petkov told reporters when announcing the decision.

He claimed that many of the expelled have worked for foreign intelligence services and their diplomatic role was just a cover up.

“When foreign governments are trying to intervene in Bulgaria’s internal affairs, we shall counteract clearly,” Petkov said.

The activities of the 70 expelled people were assessed by the respective institutions and identified as a threat to Bulgaria’s national security.

The move is forcing Russia to temporarily close its general consulate in the city of Ruse. In return, Bulgaria has decided to close its general consulate in the Russian city of Ekaterinburg.

Officially, Bulgaria’s decision is also based on the reciprocity of the number of diplomats.

The Foreign Affairs Ministry said in its statement that the number of diplomatic personnel in each of the two countries must be up to 23 diplomatic and 25 administrative-technical staff.

According to Dnevnik news outlet’s unofficial information, 150 people were working at the Russian embassy. Bulgaria has already expelled more than 10 in the past months.

Among the expelled people are the minister councillor Philip Voskresenski, the general consuls in Ruse and Varna, as well as the head of the Russian cultural centre in Sofia.

It is not yet clear what Moscow’s response will be. As the number of Bulgarian diplomats in Russia is significantly lower, a reciprocal measure might mean freezing the operations of the Bulgarian embassy.

However, the move can also have strong effect for Bulgaria’s domestic policy. Petkov’s move was not coordinated with his coalition partners – reformist Democratic Bulgaria and the pro-Russian Bulgarian Socialist Party (BSP). The latter has already announced it was surprised by the move and does not approve og it. If the BSP decides to pull back from the coalition, Petkov has no chance to form a new government.