The result is a victory for the Czech people, the prime minister says

With almost all votes counted, 77% backed EU membership.

Turnout was 55% - but there was no minimum requirement.

The BBC's Alix Kroeger in Prague says the figure is sufficient for the government to counter criticism that its campaign was lacklustre and unclear.

Prime Minister Vladimir Spidla called the result a victory for the Czech people.

However, observers say many Czechs still have misgivings about the pain and hardship in store as their economy moves towards convergence with those of their wealthier neighbours to the west.

Leader unconvinced

Those who have expressed doubts include President Vaclav Klaus, who described joining the EU as a marriage of convenience rather than love, and who declined to say how he voted.

"I am absolutely sure that my vote was the right one and you may just guess," he said.

The Czech Government is trying to bring its budget into line with EU rules.

But teachers are threatening strike action, and Nato is unhappy about cuts in defence spending.

Our correspondent says there is still much to be done before EU membership becomes a reality next year.

Hungary, Lithuania, Malta, Poland, Slovakia and Slovenia have so far voted in favour of joining the EU.

Polls are still to take place in Estonia and Latvia.