Romania’s election authority has barred far-right candidate Calin Georgescu from the presidential election re-run, escalating a constitutional crisis amid allegations of Russian interference.

The country’s electoral commission ruled on Sunday that Calin Georgescu, an outspoken critic of Ukraine and NATO, could not compete in the do-over election.

Last week, Romanian authorities expelled two Russian diplomats, military attaché Victor Makovskiy and his deputy Evgeny Ignatiev, who were accused of foreign election interference tied to Mr. Georgescu’s campaign.