Sweden’s quest to join Nato hit a stumbling block on Wednesday when Hungary said there were “ample grievances” to address before it lifts its veto.
The Nordic country “must face the music” over its criticism of the Hungarian government, said Zoltan Kovacs, a spokesman for Hungary’s Prime Minister Viktor Orban.
It came as Sweden summoned Russia's ambassador to protest at comments suggesting future Nato members would be seen as "legitimate targets" by the Kremlin.
"The new members of the hostile bloc will be a legitimate target for Russia's retaliatory measures, including military ones," the ambassador said, in what Sweden described as an attempt at interference in its Nato bid.
Hungary and Turkey are the two Nato members yet to approve Sweden’s application.
Finland’s bid was ratified by the Hungarian parliament on Monday after Turkey said it was ready to endorse it.
But in a blog post on Wednesday, Mr Kovacs said Hungary’s parliament was “right to be hesitant” about Sweden’s case.
“With Finland’s admission into Nato now secure, Sweden must face the music regarding its daunting attitude and former derogatory comments towards Hungary,” he said.
“In the case of Sweden, there is an ample amount of grievances that need to be addressed before the country’s admission is ratified.
“Swedish representatives have been repeatedly keen to bash Hungary through diplomatic means, using their political influence to harm Hungarian interests.”
Swedish politicians have expressed concerns over the state of democracy and the rule of law in Hungary, views that are widely shared in the European Union.
Brussels made €5.8 billion ($6.28bn) of EU funding available to Hungary conditional on anti-corruption measures and protecting judges from political influence.
Hungary frequently objects to such complaints and accuses critics of meddling in its affairs.
Mr Kovacs said Sweden’s “perceived moral superiority” was undermined by the burning of a Quran outside Turkey’s embassy in Stockholm, an incident that also angered Ankara.
Sweden’s Prime Minister Ulf Kristersson last week said he would seek an explanation from Mr Orban as to why Finland and Sweden were being treated differently.
Turkish President Recep Tayyip Erdogan says Sweden has not gone far enough in clamping down on Kurdish dissidents that Ankara considers terrorists.
Finland, by contrast, was credited by Mr Erdogan with taking “sincere and concrete steps” to meet Turkish counter-terrorism demands.
Finland and Sweden turned a page on decades of military non-alignment to seek Nato membership after Russia’s invasion of Ukraine.
Sweden had hoped to join Nato simultaneously with Finland but now looks likely to have to wait longer.
Both countries have been given assurances that allies would come to their aid if they were attacked in the interim.
