Belgrade (dpa) - The European Union‘s attempt to broker fresh talks between feuding Macedonian parties this week have failed after one of the parties withdrew from the planned meeting, negotiators in Brussels confirmed Thursday.The EU had summoned the leaders of four main parties to Vienna for a meeting planned Friday in a bid to keep alive a 10-month effort at defusing a massive political crisis.But the main opposition party chief, Social Democrat Zoran Zaev, said Wednesday that he would not travel to Vienna unless a blanket presidential pardon of all politicians implicated in a wiretapping and corruption scandal was revoked and early elections were delayed."We regret that the leaders‘ meeting planned for 22 April in Vienna could not take place," said the EU‘s negotiating team, comprising EU Neighbourhood Policy Commissioner Johannes Hahn and three EU lawmakers.They warned of "very serious consequences" for Macedonia if the agreement to end the crisis fails, and said that persisting rule of law issues - notably the recent presidential pardon and steps towards credible elections - must be addressed "without any further delay."Macedonian President Gorge Ivanov pardoned on April 12 dozens of politicians, including nationalist Prime Minister Nikola Gruevski, implicated as corrupt or involved in alleged illegal wiretaps of hundreds of thousands of Macedonians.The pardon annulled months of efforts by a special prosecutor assigned to investigate the allegations as part of the agreement the EU brokered between Gruevski, Zaev and two ethnic Albanian party leaders in 2015.Ivanov has so far resisted pressure from the opposition, which staged nationwide protests, as well as from the EU and the United States to revoke the pardon.On Thursday, however, the state news agency MIA quoted him as saying that he was consulting experts "on a legal solution" to the situation in the wake of his move.The other cornerstone of the deal, early polls, were initially scheduled for April 24, halfway through Gruevski‘s term, but were delayed to June 5 amid opposition complaints that conditions were still blatantly unfair.Zaev and the opposition, however, contend that conditions for free elections are still not met and want the date pushed back again.Gruevski‘s VMRO party, in power since 2006, refuses to budge and has dissolved parliament, confirming the June 5 election date.The opposition accuses Gruevski and VMRO of abusing their hold over all levers of power in Macedonia - police, courts, the economy and media - to ensure another electoral triumph and continue their reign.