Russia is waging a covert propaganda campaign to torpedo a referendum in Macedonia this weekend which could pave the way for the small Balkan country to join Nato and the EU, diplomats and analysts warned.

Macedonians will vote on Sunday on whether to change the name of their country to North Macedonia, resolving a 27-year diplomatic standoff with Greece.

Athens has always objected to the country calling itself Macedonia, arguing that it implies territorial claims on its northern region of the same name.

But Moscow is vehemently opposed to Nato enlargement in the Balkans, which it regards as its sphere of influence, and has allegedly flooded social media in Macedonia with false accounts calling for a boycott of the referendum.

Thousands of fake Twitter and Facebook accounts with the hashtag #Bojkotiram, meaning "boycott" in Macedonian, have appeared in recent weeks, according to Macedonia's Investigative Reporting Lab.

The objective appears to be to reduce the turnout of the referendum to under 50 per cent of eligible voters, meaning it would lack legitimacy.