Macedonia's opposition was set to lead a major anti-government rally on Sunday in the troubled Balkan country, which is struggling through a deep political crisis and an outbreak of violence.

The protests are the culmination of months of wrangling between conservative Prime Minister Nikola Gruevski and his centre-left opponents, which has already sparked clashes on the streets of the capital Skopje.

The country's troubles deepened last weekend with a shootout in the northern town of Kumanovo between police and ethnic Albanian rebels that left 18 people dead, including eight police officers.

It marked the worst unrest in the former Yugoslav republic since its 2001 conflict between the government and ethnic Albanian guerillas.

The opposition Social Democratic Union of Macedonia (SDSM), led by Zoran Zaev, is calling for the government to resign, accusing the ruling party of wiretapping 20,000 people, including politicians, journalists and religious leaders.
Zaev has over recent months released snippets of the alleged recordings that appear to show widespread government corruption, a murder cover-up and other wrongdoings.

His party has also boycotted parliament since an election in April last year, in which it claims Gruevski's VMRO-DPMNE party committed fraud.

"The time has come to show that we no longer want to live in a state led by Gruevski. See you Sunday," said a SDSM statement ahead of the protests, expected to attract thousands.

Gruevski however has remained defiant, insisting in an interview late Saturday that he would not resign.

His government denies making the phone recordings released by Zaev, but not that the voices are authentic -- although it says some are heavily edited or out of context.

The government in turn accuses Zaev and his followers of spying and of wishing to destabilise the country and is due to hold a rival street protest on Monday.

- 'Maneuvre of survival' -

Gruevski, Zaev and ethnic Albanian party leaders held talks this week under global pressure to resolve the crisis, which could further hamper Macedonia's already stalled bid for membership of the European Union and NATO.
All sides pledged to condemn violence and support democratic values, but there was little sign of a serious resolution.

Two ministers and the intelligence chief resigned on Tuesday, having all been accused of involvement in the wire-tapping scandal.

But Muamer Pajaziti, a Macedonian professor on European integration at Pristina University, said the resignations were only "a maneuvre of survival" by an increasingly unpopular government.

"The opposition and the public will not accept it as a solution. There is a critical mass for change led by the opposition. Slowly, on a larger scale, there are preparations for a broad anti-government coalition," Pajaziti told AFP.

Thirty alleged gunmen, including 18 ethnic Albanians from neighbouring Kosovo, have been charged with terror offences following last weekend's shootout in Kumanovo.

Authorities claim a "particularly dangerous terrorist group" of ethnic Albanians had been planning a major attack.

But the opposition and analysts suggested the timing of the unrest was suspicious, given the huge pressure facing Gruevski's government.

Ethnic Albanians make up about one quarter of Macedonia's 2.1 million population.

Macedonia obtained EU candidate status in 2005, but is yet to begin accession talks due to opposition from Greece. Athens denies its neighbour the right to use the name Macedonia, arguing it implies a claim on the northern Greek region of the same name.