Officials in the Baltic republic of Lithuania say voter turnout is likely to pass the necessary 50 percent mark in a two-day referendum on joining the European Union.
Officials were worried that turnout might fall well below the minimum in the crucial vote about the country's future.
Lithuania's leaders held rallies and issued public statements urging people to turn out to vote.
Prime Minister Algirdas Brazauskas canceled a foreign trip and called on Lithuanians not to miss what he described as an opportunity that comes only once in the history of a nation. Prominent leaders of parliament have also issued public appeals.
Recent opinion polls indicate around 65 percent of Lithuanians do favor entering the union. But voter apathy runs deep, after a decade of difficult economic reforms in the transition from the country's Soviet past.
The Soviet Red army occupied Lithuania in 1940 along with neighboring Estonia and Latvia, which are due to hold their own referendums on EU membership in September.
Polls indicate there is more opposition to the European Union in those countries, because some people view joining as a new form of foreign domination over their affairs.
But most political leaders favor the move, saying it is clearly in the economic interests of the small nations on the Baltic Sea north of Poland.
Poland and Slovakia are also to hold their own referendums on EU membership soon. Slovenia, Malta and Hungary have already approved the move.
In all, 10 more countries could join the European Union next May, most of them Eastern European states that were formerly ruled by communist regimes.