Custom workers around Greece began an open-ended strike on Monday, forcing the closure of all refineries, border stations, ports and airports throughout the country.
The strike, which was called in protest against the government's plans for severe salary cutbacks for civil servants, caused serious disruptions in food and fuel supplies.
Union officials said customs will operate with skeleton personnel who will only carry out inspections of imports and exports of perishable food items and items of national importance such as military supplies, medicine and fuel for hospitals.

Shares fell 2.1 per cent Friday on the Seoul stock exchange on general recession fears. South Korea's won dropped against the dollar.
When the Spirit rover landed on Mars five years ago, no one expected it or its sister rover Opportunity to make it to their first birthdays, let alone their fifth.
Amelie Mauresmo fell victim to a leg injury after less than half an hour on court Friday to hand over a 4-0 victory which put French compatriot Marion Bartoli into the final of the Brisbane International.
Mumbai-based movie Slumdog Millionaire won five prizes Thursday night at the Critics Choice Awards, cementing its position as a surprise favourite just as the Oscar season moves into high gear.
After the Taipei Zoo received two giant pandas from China, another Taiwan zoo said Friday it is seeking to receive a pair of pandas from China.