Tens of thousands travel to Greece's islands every year to celebrate orthodox Easter with their families. This marks the start of the high season for the tourism sector, an industry that provides one in five jobs in the recession-hit nation.

"None of the ferries scheduled to depart from (Greece's main port) Piraeus this morning has left," a coastguard official said, adding at least five ferries had been cancelled so far.

Industry groups and politicians from the main parties had urged the seamen to call off their labour action, saying it would hurt business in a country that has entered its fifth straight year of economic contraction.

"It will destroy the Easter tourist business for all the Greek islands ... It will not allow thousands of farmers to sell their products at a time when things are very difficult," said Vassilis Korkidis, president of the National Confederation of Greek Commerce.

"We are constantly hostages to strikes and protests which the only result is the destruction of one social group by another labour group," he said.

The ferry workers, who have rejected reforms to their pensions and health care funding as well as plans to open up the sector, said they had no choice but to walk off the job.

"We understand the problems that the strike causes. Our strike will have consequences," said the president of the Seamen's Federation, Antonis Dalakogiorgos.

"But we have no other options as the government introduced already finalised plans right in the middle of Holy Week and just as parliament is to be dissolved, and we are officially on our way to elections."

Some ferries were departing from smaller ports as the industrial action was not in force everywhere, said the Greek coastguard official, who could not assess the overall impact of the strike.

The Greek Orthodox Church celebrates Easter Sunday on April 15. The official holiday starts on Friday and many travel a few days before to spend the week with their relatives.

(Reporting by Gina Kalovyrna and Lefteris Papadimas; Writing by Ingrid Melander; Editing by John Stonestreet)

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