Macedonia's short history of independence has been a troubled one — and its political turmoil appears to be getting worse.

The government in this Balkan nation of about 2 million people is reeling from a massive wiretap scandal and a gunbattle between police and ethnic Albanian gunmen that left 18 dead in a border town a week ago. In a region with a long and bloody history of ethnic conflicts and political instability, the developments have caused consternation both domestically and abroad.

Months of accusations between rival politicians locked in a power struggle have plunged the country into one of its deepest political crises since Macedonia gained independence from the former Yugoslavia in 1991.

Potential trouble looms again on Sunday, when the opposition plans an anti-government rally billed as the largest Macedonia has ever seen in the capital, Skopje. The protests are supposed to continue for days, and a rival pro-government protest has been called for Monday.

Sunday's opposition rally "will be a historic day of reckoning for the current government of Macedonia," said Nikola Dimitrov, a former national security adviser. "The increasingly authoritarian regime of (Prime Minister Nikola) Gruevski will face a crowd of citizens craving freedom, democracy, rule of law and accountability."

Dimitrov, now a fellow at The Hague Institute for Global Justice, predicted that "in an all-or-nothing situation, (the government) will be ready to pay a very high price to survive."

At the heart of the crisis is a massive cache of wiretapped conversations that the head of the opposition Social Democrats, Zoran Zaev, has been releasing since January. Zaev claims that Gruevski, in power for nearly a decade, was behind the mass wiretapping of more than 20,000 Macedonians, including ministers, politicians, police, journalists, judges, foreign ambassadors and religious leaders.

Those conversations, which Zaev said were leaked to him by "patriots" in the domestic intelligence service, purport to reveal corruption at the highest levels of government, including the mismanagement of funds, spurious criminal prosecutions of opponents and even attempted cover-ups of killings. He has demanded that Gruevski resign and new elections be held.

Opposition parties have been boycotting parliament for nearly a year since accusing the governing coalition of fraud in the April 2014 election.

Gruevski, who has won successive elections since 2006, angrily rejects the accusations. He accuses Zaev of participating in a coup plot backed by unnamed foreign spy agencies seeking to overthrow his conservative government.

Some Macedonians are worried.

"I am afraid that Macedonia could enter into civic conflict with unpredictable consequences," said Julijana Petrovska, a 64-year-old retired economist. "People are so stubborn ... and divided that things could get out of control easily."

But others blame the opposition for creating instability.

Zaev "started to publish recordings he got from foreign spies and now he wants to seize power illegally, without elections," said Jovan, a 23-year-old law student who would only give his first name for fear of reprisals. "He is the one the most responsible for this crisis."

The government has come under growing criticism from the West, including from the 28-nation European Union, which Macedonia hopes to join one day. EU officials have expressed concern over the harassment of the press and apparent meddling in court cases in Macedonia, among other issues.

The ambassadors of Britain, Germany, France, Italy and the EU met Gruevski recently and issued a strongly worded statement saying the government "has not made progress toward accounting for many allegations of government wrongdoing" arising from the wiretap disclosures.

"Continued inaction" will undermine the country's efforts to join the EU and NATO, they said.

The government says it's doing what it can. On Thursday, Gruevski attended a Western ambassador-brokered meeting with Zaev and the heads of two ethnic Albanian parties in the first direct talks since the political crisis began in January. The four agreed to meet again Monday and to ensure that future demonstrations are peaceful.

The interior and transport ministers, Gordana Jankuloska and Mile Janakieski, and top intelligence chief Saso Mijalkov — a relative of Gruevski — resigned a few days ago, saying they did so to calm the situation. The three were the voices most heard on the recordings.

Meanwhile, the ghost of Macedonia's brief 2001 armed conflict between government forces and the country's ethnic Albanian minority, which fought for greater rights, hovers over the country once more.

Clashes in the border town of Kumanovo earlier this month killed 10 gunmen and eight police and wounded 37 police. Some gunmen wore insignia used by ethnic Albanian rebels during their insurgencies in Serbia and Macedonia in the late 1990s and early 2000s.

It is still unclear how the fighting in Kumanovo began. The government said police forces mounted an operation after tracking an armed group of about 50 men to a house there. Last month Macedonian police said a smaller group attacked a border watchtower, briefly taking two Macedonian border guards hostage before releasing them unharmed.

Political analyst Saso Ordanovski said he thinks the gunmen were mercenaries.

"Somebody paid them to draw attention away from what is going on at the moment in the country," Ordanovski said. Gruevski, he argued, "is the one who benefits the most from the incident ... He is facing the growing revolt and demands from abroad that he must do something."

Ali Ahmeti, who heads the ethnic Albanian junior government coalition partner, said he had been in contact with the gunmen but it was unclear what their motives were. He said they had asked for his help in brokering their surrender. Saying that most ethnic Albanians do not back an insurgency, Ahmet called for an international investigation into the clashes.

Dimitrov, the former security adviser, said there was only one way to resolve the crisis.

"Regardless of how much time it will take, and how difficult it will be, there can only be one sustainable outcome: an interim government to clean up the system, introduce robust checks and balances, promote justice, and prepare for free and fair elections," he said.