SOFIA, Bulgaria (AP) -- Thousands of flag-waving Bulgarians took to the streets of the capital, Sofia, and other major cities on Saturday to protest government plans to adopt the euro and to demand a referendum on the new currency.

The protesters, led by civic groups and nationalist parties, sang patriotic songs and shouted slogans like "Freedom for the Bulgarian lev" and "The future belongs to sovereign states." The anti-euro rally came four days before the Balkan country is expected to receive green light from Brussels to enter the eurozone.

The demonstrators in Sofia carried flags of the pro-Russian Vazrazhdane party and a huge banner that read "The battle for the Bulgarian lev is the last battle for Bulgaria."

An increased police presence kept the protest peaceful.

Bulgaria joined the European Union in 2007 and remains of its poorest members, plagued by years of instability that has fueled euroscepticism among its 6.4 million citizens. Disinformation campaigns from home and abroad have added fears of economic changes that could bring more poverty.

President Rumen Radev encouraged the anti-euro voices by proposing earlier this month a referendum on the currency, citing public concerns over inflation and purchasing power.

The proposal was turned down by the pro-European majority in parliament, which accused Radev of acting in favor of Moscow with his last-minute attempt to sabotage the euro adoption, aimed at deepening European integration amid growing geopolitical tensions.