Ukraine has urged its ethnic Hungarian citizens to ignore “idiotic myths” about dangers to their safety amid a row between Budapest and Kiev that has sparked diplomatic expulsions and threats to Ukrainian co-operation with the EU and Nato.

Relations deteriorated sharply last year when Ukraine moved to restrict the amount of non-Ukrainian language teaching in its schools in what it called a bid to boost the education and job prospects of ethnic minorities and the social cohesion of a country that is fighting an undeclared war with Russia.

Hungary and Russia were the strongest critics of the changes, and they were further angered by the Kiev parliament’s recent preliminary approval of a bill to strengthen Ukrainian as the country’s state language.

Budapest says the reforms discriminate against 120,000 or so ethnic Hungarians who live in the western Ukrainian region of Zakarpattia, which was part of the Austro-Hungarian empire until 1918.

The dispute intensified when footage emerged last month of people receiving Hungarian passports and swearing an oath of loyalty to Hungary at its consulate in Zakarpattia, while being told not to tell Ukrainian officials about their dual citizenship, which is not recognised by Ukraine’s constitution.

Each country subsequently expelled one of the other’s diplomats, the Ukrainian nationalist website Myrotvorets published details of hundreds of ethnic Hungarians who allegedly have dual citizenship, and a citizens’ petition appeared on the Kiev parliament’s website calling for Hungarians to be deported.

‘Death list’

Hungary called the Myrotvorets post a “death list” because two figures with pro-Russian views were killed in 2015 after their addresses were posted by the website; Budapest also denounced the petition and what it claimed were Ukrainian troop movements in Zakarpattia.

On a visit to the region on Saturday, Ukrainian foreign minister Pavlo Klimkin told ethnic Hungarians to ignore “idiotic myths” about threats to their safety.

“No one intends to punish anyone for dual citizenship...and these petitions that are really worrying the Hungarian community - of course we condemn them. How can one talk about deporting our own citizens?”

Of the list on the Myrotvorets site – which claims to reveal identities of people who threaten Ukraine’s national security – he added: “I’m categorically against pointing the finger at Hungarians as if they were traitors...or accusing them of separatism.”

Since 2011, Viktor Orbán’s nationalist government in Budapest has doled out more than one million passports – with voting rights – to ethnic Hungarians in neighbouring states.

Critics say Mr Orbán’s allies are exaggerating problems in Ukraine to burnish his reputation as a defender of Hungarians everywhere, and to distract from growing EU criticism of his rule.

Western support

Budapest has for several months blocked some contact between Ukraine and Nato, which alarms Kiev as it banks on western support in its conflict with Moscow.

Hungarian foreign minister Peter Szijjarto said this month that Ukraine’s alleged movement of military forces in Zakarpattia and its intolerance for dual citizenship showed it was not ready to integrate with either Nato or the EU. “Hungary will continue to veto these two goals of Ukraine.”