SKOPJE (Reuters) - Macedonia’s opposition Social Democrats urged the president on Monday to give them a mandate to form a new coalition government and to rebuff calls by the ruling conservatives to hold a new election.

As a midnight deadline expired, the conservative VMRO-DPMNE party announced it had failed to reach agreement on a renewed coalition with ethnic Albanians after a December election.

The VMRO-DPMNE, in power from 2006 to 2016, said the most “mature solution” would be fresh elections, but it remained possible that President Gjeorge Ivanov would pass the mandate to Zoran Zaev, leader of the second-placed Social Democrats (SDSM).

Neither the VMRO-DPMNE nor the SDSM can form a government without the support of ethnic Albanians, who have united around a set of demands that appeared to have proven too much for VMRO-DPMNE leader Nikola Gruevski.

He has been at the centre of a political crisis for the past two years, triggered by a surveillance scandal that forced his resignation a year ago.

Social Democrat leader Zoran Zaev told reporters: “I expect Ivanov to give me the mandate to form a government. Anything else would be a violation of the constitution and the laws. The citizens chose changes.”

An official within the ethnic Albanian Democratic Union for Integration (DUI), led by former guerrilla leader Ali Ahmeti, said it was unclear what would happen next.

“The constitution is not clear on how to proceed,” the official told Reuters on condition of anonymity. “Now it is up to President Ivanov whether or not he wants to give the chance to Zaev to form the government.”

The political crisis in Macedonia is the worst since Western diplomacy dragged the country of 2.1 million people from the brink of civil war during an ethnic Albanian insurgency in 2001, promising it a path to membership of the European Union and NATO.

But Western integration has stalled, hostage to a dispute with neighbouring Greece over Macedonia’s name.

Ethnic Albanians make up about a third of the population. After the election, their leaders agreed on a joint platform for coalition negotiations, seeking among other things the elevation of Albanian as the second official language of Macedonia across the entire country.

They also sought the extension of the mandate of a special prosecutor tasked with investigating allegations of government corruption, vote-rigging and abuse of power that emerged from the surveillance scandal that brought down Gruevski.