Eastern Europe's main currencies are likely to gain sharply next week if Ireland endorses the Nice Treaty on Saturday, according to a Reuters poll of analysts.
Conversely, a second No vote could badly dent the Czech crown, Hungary's forint and Poland's zloty.
Reuters polled 17 analysts and economists from regional and international banks in its survey.
The zloty is seen as the most vulnerable to a No vote; the Czech crown, which fell sharply yesterday, is predicted to rise the most if the Treaty is passed.
The three countries hope to join the EU in 2004, along with five other former communist states from the region, and Cyprus and Malta.
Analysts urged the EU to move rapidly to soothe market jitters over possible delays to enlargement if Ireland passed a No vote.