SOFIA (Reuters) - State prosecutors charged Bulgaria’s outgoing defense minister on Wednesday with failing to honor an agreement with Russia for repair of its Soviet-era fighter jets, arguing that the move had left the country without an effective air defense.

Nikolay Nenchev opened talks last year with Bulgaria’s NATO ally Poland to service the jets despite an existing contract with the maker of the jets, Russia’s Aircraft Corporation (RSK) MiG.

The RSK said the jets could not be repaired in Poland because Warsaw did not have the right to provide spare parts for the aircraft to third countries.

Nenchev denies any wrongdoing in the case, which comes amid signs of reviving Russian influence in Bulgaria, a former close Cold War ally of Moscow that is now a member of NATO and the European Union.

“I have been handed an indictment which does not worry me at all,” Nenchev told reporters on Wednesday, adding that the deal with Poland was much more profitable for Bulgaria. “I am absolutely certain, convinced in everything that I have been doing over the years.”

Nenchev was also charged with causing losses to the RSK totaling 3.7 mln euros. He described that charge as “a little strange, not to say hilarious”.

Nenchev has previously argued that sending the engines to Moscow could pose a risk for Bulgaria as the EU might follow the United States in imposing sanctions on the RSK over Moscow’s role in the Ukraine crisis.

Under Sofia’s agreement with Warsaw, Bulgaria gets two jet engines on loan for two years from Poland, which will also repair the engines of six MiG-29 jets for an estimated 6.14 million euros.

Last week the minority center-right government in which Nenchev was serving resigned following the defeat of its candidate in Bulgaria’s presidential poll, opening the way to months of political uncertainty and a likely snap parliamentary election in early 2017.

Bulgaria’s president-elect, Rumen Radev, a former air force commander backed by the opposition Socialists, favors improved ties with Moscow.

In unrelated cases over the past few weeks, Bulgarian prosecutors have charged three former energy ministers with mismanagement of the Belene nuclear plant that cost the state significant losses, and also the outgoing health minister over a vaccine deal. They have all denied any wrongdoing.