A spate of arrests, diplomatic expulsions and public humiliations has plunged relations between war-torn Ukraine and its prickly Nato neighbour Hungary to a new low.

At the heart of the row are accusations that Viktor Orban’s Fidesz government in Hungary is using the spat to fight his main political rival, the opposition Tisza party, which leads in the polls ahead of 2026 elections.

Earlier this month, Ukraine’s SBU security service announced the arrest of two Ukrainian citizens accused of spying for Hungary.

According to the allegations, backed by video and audio evidence, the man and woman were in the pay of Hungarian military intelligence, preparing for Hungarian military action in Ukraine.

Hungary then expelled two Ukrainian diplomats and Ukraine followed suit in a tit-for-tat response that has further damaged already sour relations. Hungary also arrested a Ukrainian citizen and accused him of spying.

Orban is widely seen as Russia’s closest ally in the European Union, and his government has broken ranks with his European partners by maintaining trade and opposing sanctions on Russia, refusing to allow the transit of weapons, and comparing Ukraine to Afghanistan.

Now he has accused Kyiv of trying to “vilify” his country.

All eight million Hungarian households recently received a questionnaire from the government, dubbed “Vox 2025”, inviting them to reject Ukraine’s EU membership.

Under a year ago, Orban presented himself as the only person on the planet other than the Pope, who was trying to secure an unconditional ceasefire.

But his critics depicted his so-called peace mission to Kyiv, Moscow and other capitals as an attempt to reward Russian aggression.

The day after Orban met Russia’s Vladimir Putin, Russian missiles struck the Ohmatdyt children’s hospital in Kyiv.

Three days later, the leader of the Tisza Party in Hungary, Peter Magyar, brought $40,000 (£29,000) of Hungarian medical aid to the hospital. Opinion polls suggest Magyar could oust Orban from power next April.

The man who drove the Tisza leader to Kyiv, Roland Tseber, is now a target of Fidesz attempts to accuse the Hungarian opposition party of betraying Hungary.

Roland Tseber came across as a fresh-faced, hard-working politician when I met him at a Ukrainian refugee centre in Uzhorod in April.

He was helping distribute medical aid from Hungary, working with Hungarian doctors and psychologists who have supported internally displaced Ukrainians from the eastern war zone, since 2022.

His troubles began within weeks of Peter Magyar’s visit, he told me.

In August, he heard he was banned from Hungary and, at Hungary’s insistence, from the whole Schengen zone of the EU, without explanation.

Mr Tseber’s letter to the Hungarian embassy in Kyiv went unanswered.

The leader of the far-right Our Homeland party in the Hungarian Parliament, Laszlo Toroczkai, labelled him a “terrorist”. Mate Kocsis the leader of the Fidesz faction in the Hungarian parliament, has called him a “Ukrainian spy”, long in the sights of Hungarian counter-intelligence.

“I reject all such accusations which try to link me to intelligence activities of any kind. This is ridiculous. I’m a Transcarpathian politician who works honestly and openly for his homeland and for Hungarian interests,” Mr Tseber told me in a phone interview.

As an elected, independent councillor in the regional assembly of Transcarpathia, who sits in the political group of Ukrainian President Volodymyr Zelensky’s Servant of the People party, he meets politicians of all shades, he says, including the deputy Hungarian Foreign Minister, Levente Magyar.

“I’m a Ukrainian politician and I meet with everyone. This whole situation is ridiculous. They want to drag me into this spy story. But anyone with any common sense can understand that this is absurd.”

The weakest link in the Hungarian government’s narrative is that if he was really on the radar of Hungarian intelligence, government politicians and Peter Magyar as a Member of the European Parliament would have been warned to stay away from him.

The dwindling Hungarian community in Transcarpathia has become collateral damage in the Ukraine-Hungary row.

In Ukraine’s last census, in 2001, their population was 150,000, but latest estimates suggest their number has since halved to 70-80,000. Dozens have lost their lives, fighting for Ukraine against Russia.

Another twist in the story is that a former Hungarian chief-of-staff, Romulusz Ruszin-Szendi, who’s now a prominent Tisza party politician, has come under attack from government-controlled media.

The government alleges that “a former senior figure in the defence sector” – an apparent reference to Ruszin-Szendi – was in contact with Ukrainian intelligence.

Ruszin-Szendi hit back, alleging a smear campaign. “I am a decent Hungarian citizen who has worn the uniform since the age of 14. I am shocked and saddened to know that what I and my comrades have done for our country is worth so much for you,” he addressed the government on Facebook.

Since the full-scale Russian invasion of Ukraine in February 2022, Viktor Orban has portrayed himself as a man of peace, and won the April 2022 election with a promise to keep Hungary out of the war in Ukraine.

However, a speech from 2023 that has only just been leaked by Peter Magyar tells a very different story.

Defence Minister Kristof Szalay-Bobrovniczky was recorded saying a year after the war in Ukraine began that the government had decided to break with the peace mentality and move to “phase zero of the road to war”, with a combat-ready Hungarian army.

This was the same year that many experienced Atlanticists such as Ruszin-Szendi were sacked as part of a “rejuvenation” of the military.

They were replaced by officers loyal to the government’s pro-Moscow stance.