SAO PAULO (Reuters) - A federal court sentenced Brazil’s former speaker of the lower house, Eduardo Cunha, to more than 15 years in prison on Thursday for corruption, making him the highest-profile political conviction yet in the “Operation Car Wash” scandal.

FILE PHOTO - Former speaker of Brazil's Lower House of Congress, Eduardo Cunha (C), is escorted by federal police officers as he arrives to the Institute of Forensic Science in Curitiba, Brazil, October 20, 2016. REUTERS/Rodolfo Buhrer/File Photo

The former politician’s defense team said they would appeal the decision. Cunha will remain imprisoned pending appeal.

Cunha, who drove the successful impeachment of former President Dilma Rousseff, was forced from his position as speaker in July and arrested in October on accusations he received millions in bribes from the purchase of an oil field in Benin by state-controlled oil company Petróleo Brasileiro SA.

Over 200 people have been charged in the “Operation Car Wash” probe, a far-reaching investigation that centers on bribes and political kickbacks from contracts at Petrobras and other state firms. The Supreme Court is likely to approve soon the investigation of dozens of sitting politicians.

In February 2015, Cunha, a member of President Michel Temer’s Brazilian Democratic Movement Party (PMDB) that for a decade was the main member of left-leaning Workers Party (PT) governments, defied the wishes of his own coalition to run for and win the speakership of the lower house of Congress.

Just six months later, he officially broke with the Rousseff administration, saying that she was using the Petrobras investigation as a tool of “political persecution” against him.

As speaker, only Cunha could allow impeachment proceedings to begin against Rousseff, whom critics accused of breaking budgetary laws.

He did just that in December 2015, just hours after PT deputies cast deciding votes for him to face an investigation by the House’s ethics committee for lying about bank accounts he and his wife held in Switzerland.

By May, Rousseff was impeached and Temer installed as successor. But Cunha could not shake free of corruption allegations that eventually led to his downfall.

Once he was kicked out of congress, Cunha lost the privilege given to sitting politicians that only the badly overburdened Supreme Court can try them.

His case was instead sent to crusading anti-corruption judge Sergio Moro, who has been the driving force behind Brazil’s fight against graft. Moro has a reputation for plowing through cases efficiently, with over 98 percent of his convictions in Car Wash cases being upheld by higher courts.

Cunha faces another trial for allegedly receiving $5 million skimmed from Petrobras contracts for two drillships in 2006 and 2007.

Separately on Thursday, federal prosecutors leading the Car Wash probe for the first time accused a party of the civil crime of “misconduct in political office” for taking part in the Petrobas scheme.

The authorities said they are seeking 2.3 billion reais ($731 million) from the Progressive Party (PP) for bribes its members received and for fines. Prosecutors are also demanding six sitting PP congressmen and four former deputies lose their offices and rights to run for office in the future.