Romanian prosecutors formally charged Prime Minister Victor Ponta with forgery, conflict of interest, tax evasion, corruption and money laundering in connection with his professional activities as a lawyer between 2007 and 2011, prior to when he took office in 2012.

Ponta announced on his Facebook page that he steps down from any leading position in the party until he is proven innocent of the charges brought against him.

Romanian television showed Ponta, who returned to Bucharest last week after almost a month in Turkey for knee surgery, leaving the DNA headquarters on crutches. Ponta said “I am the prime minister of this coalition and I am presenting myself in a disciplined way”.

The investigation had sparked calls for Ponta to resign. President Klaus Iohannis urged Mr Ponta to resign, but the prime minister refused.

Ponta is accused of receiving the equivalent of around 55,000 euros ($61,000) from Dan Sova, a political ally and member of parliament suspected by prosecutors of abuse of power but who also enjoys immunity. Ponta did not speak to the press after he left the prosecutor’s office on Monday.

The situation has also caused tensions within Ponta’s party, the biggest in Romania.

Romanian Prime Minister Victor Ponta resigned the leadership of the Social Democratic Party (PSD) on Sunday.

Ponta survived a vote to lift his immunity and a no-confidence vote in June.

Prosecutors said they had named the 42-year-old prime minister as a defendant in a five-week long criminal investigation, and temporarily seized control of his property.