BUCHAREST (AFP) ― Romania’s Constitutional Court ruled Tuesday that a referendum to impeach the country’s president was invalid, leaving Traian Basescu in power and dealing a blow to the center-left ruling coalition.

“The court noted that the turnout was lower than the minimum threshold required for the ballot to be valid,” the judges said.

“The ruling was adopted with a qualified majority,” one of the nine judges, Tudorel Toader, told reporters at the end of a nearly three-hour-long meeting.

Basescu, who was suspended from the presidency pending the referendum decision, is now expected to return to his office to see out the rest of his second five-year term which started in 2009.

Romania’s ruling center-left coalition USL headed by Prime Minister Victor Ponta last month launched a move to impeach centre-right rival Basescu, which led to a referendum that failed as voter turnout fell short of the required 50 percent threshold.

An overwhelming majority of voters ― 87 percent ― supported ousting Basescu, prompting the USL to contest the electoral rolls after the ballot.

Ponta blasted as “illegal” the court’s decision, alleging it violated legislation and democratic rules.

“The Constitutional Court’s ruling was illegal, unjust and politically motivated,” Ponta told a press conference, a day after sending the court updated eligible voter figures, hoping this will overturn the result.

Ponta said he would “continue to defend Romanians from a repressive and oppressive regime” allegedly embodied by Basescu.

But he will have to put up with Basescu for two more years, with presidential elections due in 2014.

Interim president Crin Antonescu too said the court’s ruling was “unjust, as it overrides the votes of 8.5 million people and the laws the court itself is citing.”

He stressed he would no longer consider Basescu a “legitimate president,” calling on Romanians to “defend their power as citizens ... and fight to put an end to the Basescu regime.”

But former center-right prime minister Emil Boc said he hoped “the ruling will put an end to the political crisis” and urged politicians on both sides to work together.

“Romania has proven to have strong institutions ― the Constitutional Court and the Prosecutor’s Office ― to name just two,” Laura Stefan, an anti-corruption expert of Forum Expert think tank, said.

The ruling, adopted by the court despite “tremendous political pressure” on judges, will be a landmark in Romania’s efforts to consolidate the rule of law, she stressed.

Some 200 demonstrators meanwhile gathered in front of the court’s headquarters calling for Basescu to be ousted.

The organizers of the protest, members of a reservists’ trade union favorable to the USL, said they would stage rallies daily and “wreak chaos” in Romania if the court invalidated the referendum.

The European Commission and the United States have voiced deep concern over the ruling coalition’s controversial moves ― notably an attempt to curtail the Constitutional Court’s powers ― to impeach Basescu which they said threatened the rule of law.

The Commission took note of the court’s ruling and urged “all political actors” to comply with the it, saying the “legal procedure to reinstate President Basescu should be respected.”

It added: “Respect for the rule of law and independence of the judiciary are essential for restoring political stability and economic confidence in Romania.”

The power struggle between the USL and Basescu has sunk the local currency and rattled foreign investors, putting economic recovery at risk.

Last week the International Monetary Fund and the EU cut back their growth forecast for this year from 1.5 percent to 0.9 percent, citing the eurozone crisis, the political turmoil in Bucharest and the effects of drought.