Johannes Hahn, the European Union's enlargement commissioner, plans to visit Macedonia on March 21 in another attempt to help break a political deadlock that has left the country unable to form a government since December's election.
A group called "For A United Macedonia" -- which supports the agenda of the nationalist VMRO-DPMNE party -- has called for a demonstration outside the EU mission's Skopje office during Hahn's visit.
The group says it wants to send "a clear message to Hahn" that members oppose a government that would "ruin the unitary character" of Macedonia by making Albanian an official language.
Three ethnic Albanian parties have demanded Albanian become an official second language as a condition for joining any coalition government.
VMRO-DPMNE leader and former Prime Minister Nikola Gruevski refused to meet those demands.
Social Democratic Union leader Zoran Zaev tried to form a coalition with the ethnic Albanian parties.
But President Gjorge Ivanov, also from the VMRO-DPMNE, refused to give Zaev the official mandate to do so.
Ivanov argued that the language issue was an attempt to destroy Macedonia's independence.