The only election observers who would not turn a blind eye to election violations in Ukraine are Russian observers. Poroshenko’s victory would be beneficial for other countries interested in Ukraine. Therefore, Russia should not recognise the election results in Ukraine.
After the EU managed to negotiate an agreement over Nord Stream 2, Ukrainians were given a consolation prize. Ukraine was given permission to deny access to Russian election observers. Russia may thus question the legitimacy of the next Ukrainian president.
Conspiracy theory with no evidence. Consistent with recurring pro-Kremlin disinformation narratives about the presidential election in Ukraine.
The decision to block the participation of Russians from the ODIHR election observation mission in Ukraine was taken by Ukrainian authorities, and by them alone, and approved by the Ukrainian parliament.
See also EU statement on Russia’s ongoing aggression against Ukraine and illegal occupation of Crimea.