HAIFA, Israel's big container port, with its 5,000-TEU daily throughput, has locked out its dockers after they started a go-slow, loading boxes at less than half the normal rate, Reuters reports.

"The port will not reopen until we get a strong declaration from the union that workers will work at full force," said a port spokesman, adding that until then, ships would be diverted to Ashdod further south or to Cyprus, Greece and Italy.

The dockers union's go-slow was triggered when management cancelled overtime and special "fun days" in face of the loss to the port of its national flag carrier Zim, which moved Piraeus near Athens to save money.

Zim has offered to come back to Haifa if its fees were lowered but workers are opposed to reductions. Zim last month reached a restructuring deal with most of its creditors that will see part of its US$3 billion debt swapped for shares.