Viktor Orbán has said he will urge the Hungarian parliament to sign off on Sweden’s Nato bid “at the first possible opportunity”, as diplomats said Hungary’s allies were “exasperated” by the country’s foot-dragging. Sweden applied to join Nato in May 2022, but its accession was delayed as Turkey and Hungary strung out the ratification process. On Tuesday night, Turkey’s parliament voted in favour of Swedish membership, but Hungary’s parliament has yet to sign off on it, despite repeated promises from senior Hungarian officials that their country would not hold up the process alone. Just as Turkey’s parliament prepared to vote, Orbán, the Hungarian prime minister, surprised allies by issuing a public invitation to his Swedish counterpart to visit Budapest for talks on the Nato accession process. “Allies are exasperated,” said a senior European diplomat, who spoke on condition of anonymity to discuss sensitive internal matters. “That Orbán offered ‘negotiation’ while Hungary never raised objections during the accession talks is outrageous.” A second senior European diplomat echoed the frustration. “I think allies expected Hungary to abide by their commitment not to be the last,” they said. “The recent moves sent shockwaves throughout the alliance, and a great dose of disappointment is there. After all, they had all the time in the world to consult with Sweden before.” Hungary – which, unlike most other Nato countries, continues to maintain a friendly relationship with Russia – has, along with Turkey, dragged out Sweden’s Nato ratification process. Although it submitted the ratification to parliament in 2022, a final vote on the matter has been repeatedly delayed, and is now the main single factor holding up Sweden’s membership. With Tuesday’s vote in the Turkish parliament, Ankara’s portion of the process is nearly complete – though the first diplomat cautioned that it was “not a done deal” as the Turkish president, Recep Tayyip Erdoğan, needed to sign the ratification. On Wednesday, as pressure mounted, Orbán said he had spoken on the phone with the Nato secretary general, Jens Stoltenberg. “I reaffirmed that the Hungarian government supports the Nato membership of Sweden. I also stressed that we will continue to urge the Hungarian national assembly to vote in favour of Sweden’s accession and conclude the ratification at the first possible opportunity,” Orbán said, without offering a concrete timeline. The Nato friction comes at a time of growing frustration in western capitals over Hungary’s blocking of long-term EU assistance for Ukraine. Ankara and Budapest had earlier also delayed Finland’s Nato accession, but Hungary’s parliament moved quickly to ratify the Finnish bid in March last year once it became clear that a vote in the Turkish parliament was imminent. Officials had expected a similar scenario to unfold in the Swedish case and are confused by the Hungarian government’s signalling. In public, Nato members have made it clear that eyes are now on Budapest. “It is now high time for Hungary to conclude the remaining steps so that we can welcome our Swedish friends to the alliance,” the German foreign office tweeted. In private, patience is running out. There is a “very negative mood” towards Hungary, said a third senior European diplomat. There is “no understanding for extra discussions or negotiations”, they said. Domestically, senior politicians from Orbán’s ruling Fidesz party have argued that continued delays to Swedish membership are justified because Sweden has, in their view, unfairly criticised the state of Hungarian democracy. Asked about frustration within Nato about Hungary’s delays, Balázs Orbán, the Hungarian prime minister’s political director, said in an email on Wednesday that “we take our Nato membership and military commitments very seriously” and that “the Hungarian government supports Sweden’s accession to Nato”. He added: “Constant political attacks on Hungary by the Swedish political, media and NGO elite raised concerns among Hungarian MPs. For this reason, we have repeatedly asked the Swedish government to engage in political consultations by visiting Hungary. Unfortunately, despite high-level Hungarian delegations visiting Stockholm, our requests have been repeatedly declined. “Nevertheless, we remain open to dialogue if Nato membership is indeed a priority for Sweden. The ball is in their court.” Officials familiar with talks within Nato headquarters say that unlike Turkey, Hungary never formally made any concrete demands when it came to Swedish membership. In his invitation letter on Tuesday to the Swedish prime minister, Ulf Kristersson, for further talks, Orbán made no direct mention of any grievances or objections. Orbán wrote: “I believe that a more intensive dialogue could contribute to reinforcing trust between our countries and institutions thus allowing to further strengthen our political and security arrangements.” The letter was met in Stockholm with surprise and caution. A spokesperson for Kristersson declined to comment on the request, saying there would be no response from the prime minister as yet. Sweden’s foreign minister, Tobias Billström, however, said that before responding the government would need to “think through what the letter signals”. After Turkey’s move on Tuesday night, there was muted celebration in Stockholm. Kristersson said: “Today we are one step closer to becoming a full member of Nato.” But there was caution over the fresh question mark over Hungary and worries over whether Erdoğan could yet demand further concessions before signing the bill into law. Sweden’s former prime minister Magdalena Andersson, who leads the opposition Social Democrats and started Sweden’s Nato process nearly two years ago, said that during her premiership Orbán promised her that Hungary would not be the last to ratify Sweden and that he had made similar pledges to Kristersson. She said: “I don’t see that there’s very much to discuss with Hungary.” She added: “We fulfil the criteria and they have promised to ratify us.” While she said Hungary had “a complicated relationship with the European Union” and acknowledged that there was much to discuss outside Sweden’s Nato membership, Andersson declined to speculate on Orbán’s motivation for stalling the process. “It’s difficult to guess why they are doing this, so I am not going to start guessing. But what I know is that it’s time for Hungary to ratify.” She said she found the influence on the country of the Sweden Democrats, whose support Kristersson’s government depends upon, “really concerning” and claimed that the far-right party saw Hungary “as a role model for a country”. Criticising her successor, she said: “The lack of leadership from the prime minister in this respect is truly worrying.” Asked whether the prime minister could give concessions to Hungary, she said: “Leading Sweden Democrats have said that they think he [Kristersson] should go and take a whisky with Viktor Orbán.”