A Romanian court has sentenced the country's most powerful politician to 3 ½ years in prison for official misconduct in a graft case.

In this Sunday, May 26, 2019, file photo Liviu Dragnea, the head of the ruling Social Democratic party leaves a voting station after casting his vote in the European Parliament elections, in Bucharest, Romania. (Photo: AP)

Monday's sentencing of Social Democratic Party leader Liviu Dragnea comes after a 2018 conviction linked to the employment of two party members at a public agency.

Dragnea, already blocked from being prime minister because of a 2016 conviction for vote-rigging, is expected to be imprisoned within 24 hours.

Dragnea's party suffered huge losses in European Parliament election on Sunday, falling to second place behind the opposition National Liberal Party.

Additionally, a non-binding referendum called by President Klaus Iohannis seeking to pressure the government into dropping efforts to water down anti-corruption measures won support from 80% of voters on Sunday.