Bucharest, Romania (CNN) -- Romania's leftist government began impeachment proceedings Wednesday to suspend President Traian Basescu. In a motion filed in parliament, the ruling coalition accused the president of violating the country's constitution and overstepping his authority.
The motion is the latest in a series of attacks over the past month between Basescu and Prime Minister Victor Ponta.
A vote on the motion scheduled for Friday is expected to pass, given that the coalition holds a comfortable majority in parliament. If this were to happen, Basescu would be suspended for a month and the country would hold a referendum within 30 days on whether he should remain in office.
During the president's suspension, National Liberal Party leader Crin Antonescu, who is also the newly appointed president of the Senate, would assume the interim presidency.
The ruling alliance of Social Democrats and Liberals this week passed a law making it easier for the coalition to impeach Basescu.
In addition, Ponta accused some Constitutional Court judges of political bias and incompatibility and suggested that they be replaced.
The court, in turn, said Ponta was trying to dismantle it and threaten its independence.
EU Commissioner for Justice Viviane Reding said on Twitter that she was "seriously concerned about the recent attacks on the independence of the Constitutional Court of Romania."
On Tuesday, the ruling coalition sacked the heads of both chambers of parliament, who were Basescu allies, and replaced them with politicians close to Ponta.
Also Tuesday, the coalition dismissed the country's ombudsman, whom it accused of political bias. The newly appointed ombudsman, Valer Dorneanu, is a former Social Democrat member of parliament.
Basescu told reporters Tuesday that the country's current situation can be compared with riots that occurred in June 1990 by miners who staged violent demonstrations in the streets of Bucharest with the goal of bringing about political change.
"I warn the politicians that by breaking the country's laws and constitution, the country and its 22 million people are put in an extremely difficult situation," Basescu said.
The impeachment motion is to be read Thursday during a special meeting of parliament.
Coalition leader Antonescu has invited Basescu to address parliament directly on the matter.
The political developments have raised concern from some observers about the state of democracy in Romania. U.S. Ambassador to Bucharest Mark Gitenstein said he was "deeply concerned" that the independence of the country's democratic institutions was under threat.
Romania's government became the object of international criticism after Ponta was accused of plagiarizing his doctoral thesis. Ponta dismissed the accusation as a political attack from Basescu.
The two men also argued over who was entitled to represent Romania at last month's meeting of the European Council in Brussels. Ponta received Parliament's vote to go to Brussels on behalf of the country, but the Constitutional Court ruled that president Basescu had the right to attend the event. In the end, the prime minister ignored the court's ruling and traveled to Brussels.
The coalition government has come under criticism recently for ordering that Romania's Cultural Institute report not to the president, as it had been doing, but to the Senate. The institute is known for promoting Romania's cultural values and projects abroad as well as for supporting its artists, writers and cultural movements.
The country's civil society and anti-corruption agencies addressed on Wednesday a letter to the president of the European Commission, Jose Manuel Barroso, expressing concern over this "unprecedented attack" on the rule of law.
On Wednesday evening, some 300 people protested in front of the Government and at University Square in Bucharest. While some called for Basescu and Ponta to step down, others expressed concern over the threats to the country's democratic institutions.
Ponta recently acknowledged that Romania is going through a credibility crisis at an international level but predicted the turmoil would end after this fall's parliamentary elections.