Swiss voters on Sunday narrowly approved a law giving one billion Swiss francs (630 million euros, 827 million dollars) in aid to new EU members in eastern Europe, according to final referendum results.
The proposal was approved by a margin of 53.2 percent of voters in Sunday's referendum.
It was supported by the government and a large majority of the non-EU country's political parties and economic organisations, but opposed by the popular right wing, represented by the populist Swiss People's Party (SVP).
"It's stupid for taxpayers to pay billions to eastern Europe," said Hans Fehr, head of an association defending Swiss neutrality and independence (AUNS) that traditionally opposes closer ties with the European Union, ahead of the vote.
"It will only fuel bureaucracy," said Fehr, who is also a parliamentarian for the SVP, the country's largest single political grouping and staunch opponent of closer ties with the European Union.
About half of the 10-year development package was due to go to Poland, ahead of Hungary and the Czech Republic.
The grant was due to be spent on chosen projects, ranging from fighting corruption, health care and cleaning up the environment, to promoting private enterprise including investment in small and medium sized companies.