Balkan state ready to become 28th member of the European Union as referendum delivers an overwhelming yes vote

Croatia has voted to join the EU by a sweeping majority, delivering a greater than expected yes vote in a referendum watched nervously in Brussels for fear of a backlash.

With the EU facing its worst ever crisis, with the sovereign debt emergency sapping its self-belief, and Greece's membership of the euro in doubt, there were fears that the pessimism engulfing Europe would dampen pro-EU sentiment in Croatia.

But the referendum held on Sunday on joining the EU next year as the union's 28th member was supported by up to 67%, according to official projections based on around 40% of the vote.

The solid yes vote was higher than what had been predicted in the opinion polls. The endorsement means that Croatia, barring any last-minute hiccups, will become the EU's 28th member country in July next year, symbolising its break with the Balkans and former Yugoslavia and anchoring it strongly in the European mainstream as well as Nato.

Senior politicians in Zagreb described the referendum as historic.

Only once before in the country's 20 years of independence has a referendum been held, that to secede from Yugoslavia in 1991.

Despite the EU being at its lowest ebb arguably ever, leading Croatian figures are relieved that the country is bolting into the union before the doors close on further expansion.

The surge in enlarging the union by 12 countries over the past decade is over. Turkey's bid to join — it started negotiations at the same time as Croatia in 2005 — has stalled. The rest of former Yugoslavia and Albania are keen to join and Brussels continues to pay lip-service to that aim.

But it is likely to be a decade at least before Serbia, Bosnia and the rest are admitted, if at all. A no vote on Sunday would have been seen as a disaster, relegating Croatia to a Balkan quagmire.

Voting turnout, however, was low, barely scratching half the electorate, although analysts said the figure was inaccurate because the electoral rolls remain loaded with "dead souls". But participation was considerably higher in a general election last month.

"The turnout could have been better," said the prime minister and social democrat leader, Zoran Milovanovic. "It's not brilliant. Probably because of the situation in the country."