Romania's high court on Thursday sentenced the leader of the ruling left-wing Social Democrat party (PSD), Liviu Dragnea, to three-and-a-half years in prison over a fake jobs scandal.
The court's decision can be appealed but is expected to weaken his ability to influence national politics.
Dragnea, 55, who is not yet in custody, is widely acknowledged to be Romania's most powerful politician and is thought to hold substantial sway over the government of Prime Minister Viorica Dancila.
Dragnea wasn't able to become premier himself because of a two-year suspended prison sentence for vote-rigging dating back to 2016.
He is also under investigation for fabricating documents to obtain EU funds in a third case.
Anti-corruption prosecutors in Thursday's case had accused Dragnea of using his influence to keep two women on the payroll of a child protection state agency, even though they were working for the PSD.
Dragnea, who is currently president of the lower chamber of the Romanian parliament, has repeatedly denied any wrongdoing.
The court ruling comes days after a protest staged by the PSD in support of the government and against alleged abuses on the part of prosecutors and the judiciary.
"Each one of you can be reached by the long arm of the parallel state," Dragnea told the crowd on June 9, taking aim at "corrupt prosecutors", the head of the Anti-corruption Prosecutor's Office (DNA) Laura Codruta Kovesi and magistrates whom he accused of links to the secret services.
- Pressure on magistrates ?
Since the PSD returned to power at the end of 2016, Dragnea has led the party's charge against what it says are abuses by the judiciary.
In the weeks leading up to Thursday's sentence, judges and prosecutors denounced increasing pressure on them and reacted sharply after Liviu Dragnea compared prosecutors with the communist-era secret police during a TV interview.
"Magistrates are right to be outraged", centre-right president Klaus Iohannis told reporters last week.
"How can a politician, who is also a felon, dare to threaten prosecutors on TV?", asked Iohannis, who frequently clashed with the government.
Romania's parliament, dominated by the PSD, voted through this week a number of controversial changes to the penal code which critics say hamper the fight against corruption and are tailor-made to benefit Dragnea.
"The Social Democrats (PSD) want to hobble the power of the judiciary, which is very serious," Iohannis told journalists after Monday's special evening sitting of parliament to pass the measures.
- EU 'concern' -
Thousands of Romanians took to the streets on Wednesday evening to protest against the new amendments, calling the government "thieves" and chanting: "We won?t give up". Eight people were detained after scuffles with security forces.
The European Commission, which has Romania's judiciary under special monitoring, told AFP on Thursday that it is "following closely and with concern the ongoing developments in Romania".
The government scored a victory last month with a Constitutional Court verdict which ordered Iohannis to approve the sacking of top anti-corruption prosecutor Laura Kovesi.
Iohannis said that he needs more time to reflect on the judgement but local media reports say if he attempts to delay Kovesi's sacking, the PSD may launch impeachment proceedings against him.