Poland said today (27 March) it would bring charges against two Russian air traffic controllers over a 2010 plane crash which killed then Polish president Lech Kaczy?ski, a move likely to damage bilateral relations already strained by the Ukraine crisis.

Prosecutor Ireneusz Szelag from the District Military Prosecutors’ Office told a news briefing an investigation so far had established that the main cause of the crash was the failure of the plane’s crew to respond adequately to bad weather.

But Szelag said prosecutors had begun the process of presenting two charges to air traffic controllers involved in guiding the aircraft in to land at an airport in Smolensk, western Russia.

“Experts’ opinions have given us reasons to issue on 24 March a decision to charge […] two Russian citizens, members of the flight control group,” Szelag said.

He said one charge was bringing about the direct threat of an air traffic disaster, and the second was unintentionally bringing about an air traffic disaster.

It is very unlikely that Russia would agree to the officials’ extradition to Poland to stand trial.

Poland has been one of the most outspoken critics of Russian policy towards a pro-Russian separatist rebellion in eastern Ukraine, joining Western allies in accusing Moscow of supplying help to the insurrection – something the Kremlin denies.

Szelag did not name the people to be charged, and declined to give details about what the controllers are alleged to have done, or failed to do, that contributed to the crash.

The plane crash, which killed eight crew members and 88 passengers, including Kaczy?ski and a number of high-ranking Polish officials, shook Polish society.

Kaczy?ski was on his way to a commemoration at Katyn, the site in western Russia where during World War Two the Soviet secret police executed thousands of imprisoned Polish military officers and buried them in mass graves.