Romania's President Traian Basescu has been suspended as part of a power struggle with the country's prime minister, who says the president has overstepped his authority and interfered with the government's work.

A total of 256 lawmakers out of 432 voted on Friday in favor of the move. Mr. Basescu is now subject to a national referendum on July 29 to determine whether he should lose his job permanently. In a reaction statement, Mr. Basescu says he is preparing for the referendum.

Crin Antonescu of the ruling Liberal Social Union has been appointed interim president.

The center-right Mr. Basescu survived a similar vote in 2007, but analysts say he faces a tougher challenge now, partly because of his declining popularity in the nation of 19 million people, at a time of economic crisis.

Additionally, a recently adopted law requires a simple majority of votes to push him out. Before, a tougher standard was needed to validate the referendum outcome.

The bitter feud between Mr. Basescu and his rival, the center-left Prime Minister Victor Ponta, has thrown Romania into its worst crisis since it emerged from communist dictatorship over two decades ago. The two men recently disagreed on who should represent the country at a European Union summit.

The president has also been accused of harsh remarks toward Roma, also known as gypsies, and disabled people — although he has denied wrongdoing.

The United States has led Western concern that Mr. Ponta's coalition government, which took power in May, has been eroding Romania's freedoms.

U.S. State Department spokeswoman Victoria Nuland in a statement late Friday expressed concern about recent developments in Romania that threaten democratic checks and balances and weaken independent institutions, such as the courts. The statement urged that the process of removing the president be conducted in a fully fair and transparent manner.

Some analysts say the effort to remove President Basescu is illegal. His supporters say the move is an attack on democracy in Romania and they are calling for the prime minister's resignation.