VIENNA -- Austria's referendum on European Union membership Sunday is too close to call, but a "no" vote could influence similar polls in Scandinavia this year and may dent East European hopes of joining by 2000. Chancellor Franz Vranitzky's government was stunned by an opinion poll last week showing EU support slipping to 48 percent with "no" voters closing in on 46 percent. A survey Monday put voters who had definitely made up their minds neck-and-neck at 31 percent for and against. Foreign Minister Alois Mock has warned that a "no" vote would relegate Austria to second-class status. Business leaders fear it would cut Austria off from lucrative European markets and hurt the Alpine republic's manufacturing base. Sunday's result will be watched closely by Finland which holds its EU referendum Oct. 16, and in Sweden and Norway which have theirs in November. "The consequences of a 'no' vote could be far-reaching," a commentary in Austria's Kurier newspaper said Wednesday. "It could send a signal to the northern countries," the mass-circulation paper said, "and overturn the whole process of EU enlargement. It could also postpone the entry of East European states later into the next century."That may be an exaggeration, but analysts in the three Nordic countries believe a strong "no" vote in Austria, in the heart of Europe, could strengthen the hand of EU opponents. Olof Ruin, professor of government at the University of Stockholm, said a "no" from Austria which, like Sweden, is neutral, would have some impact. "It would probably strengthen the 'no' side here but it may not have fundamental consequences because Austria is far away." The outcome of Finnish and Swedish referenda would be far greater in any chain reaction effect, analysts said, but in Eastern Europe, the Austrian result is viewed as more important. Austria prided itself during the Cold War as a neutral stepping stone between the capitalist West and Communist East and Vienna has pledged to help Poland, the Czech Republic, Hungary and Slovakia to join the European Union.A spokesman for the Czech Foreign Ministry said that the result of the Austrian referendum is definitely a "relevant decision" to the Czech Republic. "It doesn't mean that it could affect the way Czechs decide, but it's something that should be taken into account." Hungary, which formed part of the Austro-Hungarian Empire before independence after World War I, said an Austrian "no" vote could hinder Budapest's EU aspirations.