Romanian Prime Minister Victor Ponta faced a corruption investigation and an internal revolt on Friday, as President Klaus Iohannis called for his resignation amid the allegations.

“In my opinion, it is an impossible situation for Romania that the Prime Minister is under prosecution. On the other hand, the worst thing for Romania right now would be a political crisis,” Iohannis said, according to Romania Insider.

“I ask Prime Minister Victor Ponta to resign,” he added.

Ponta is accused of forgery, tax evasion and money laundering during his time as a lawyer in 2007-2008, before he came to power in 2012. At the time, he was also a lawmaker for the ruling Social Democratic party. He allegedly forged invoices from a law firm to buy luxury apartments and a sports car.

The investigation is being conducted by the country's National Anticorruption Directorate (DNA), which has arrested several high-profile Romanian politicians in recent months. In March, Darius Vâlcov resigned as the finance minister after corruption charges were leveled against him. Former senior cabinet minister Liviu Dragnea was also convicted in May of electoral fraud relating to a 2012 attempt by Ponta’s party to impeach the then president Traian Băsescu.

The latest investigation has spread to include Ponta’s mother, sister, brother-in-law and father-in-law.

Ponta refuted the charges and struck back against Iohannis in a Facebook post on Friday: “I respect President Iohannis’ public stand, but I was appointed by Romania’s Parliament and only the Parliament can dismiss me.”

Shortly after prosecutors announced they were charging Ponta, the opposition National Liberal Party (PNL) reportedly filed a vote of no confidence against his leftist government. Ponta’s party still commands a majority in parliament.

PNL's members supported Iohannis in the 2014 presidential elections, and have been attempting to oust Ponta and name a new prime minister from their party, according to Romania Insider.

Romania is thought of as one of the most corrupt countries in the European Union. A report from European fraud watchdog OLAF found that over a third of all corruption probes in 2014 centered on Romania, Hungary and Bulgaria.