A junior partner in Macedonia's ruling alliance on Wednesday joined the opposition's boycott of the June 5 elections, that were called early in line with an EU agreement.
The DUI, one of the two main parties from the ethnic Albanian minority in Macedonia, confirmed that it will not take part in the polls, which were already delayed once amid opposition complaints.
The ruling nationalist VMRO was yet to react, but DUI's move puts additional pressure on it to accept a delay in the elections and more reforms towards a fairer vote, in keeping with opposition demands.
Early elections are part of a broad agreement the European Union brokered between VMRO chief Nikola Gruevski and opposition Social Democratic Union (SDSM) leader Zoran Zaev in June 2015.
The elections are supposed to end a long-running political crisis that erupted when the SDMS refused to acknowledge the result of snap elections two years ago, accusing then prime minister Gruevski of rigging them.
SDSM also accuses Gruevski of abusing the media and security services to cement his hold on power. In early 2015, Zaev released batches of material allegedly proving that Gruevski's authorities illegally wiretapped 20,000 people.
Although Gruevski quit in January after a decade as prime minister - also part of the EU-brokered deal - making way for a cabinet of technocrats, he and VMRO are still in control and he seeks to return to office with another election win.
Polls were initially planned for April 24, but in February the date was moved to June 5 as SDSM insisted that there was still too much room for manipulation.
Meanwhile, President Gorge Ivanov on April 12 announced the pardon of dozens of politicians - including his ally Gruevski - who were implicated in the wiretapping scandal, effectively nixing half a year of efforts by a special prosecutor.
The move triggered nationwide protests, which occasionally turned violent. Macedonia, which barely escaped an all-out civil war following an Albanian insurgency for more rights in 2001, is still deeply divided politically and along ethnic lines.
An attempt by the EU to continue brokering the talks between Gruevski, Zaev and the two main ethnic Albanian leaders failed on April 22.