Traffic jam off the port of Piraeus

More than 25 cargo ships were waiting outside the port of Piraeus on Wedneday, unable to approach it as the Greek port pilot service called a 48-hour strike, creating major delays and serving a blow to the port's international prestige.

Eventually the strike was ruled illegal in court, but this isn't the first time the pilots have decided not to work in recent months.

According to Piraeus Port Authority (OLP) data, the port was all but closed for a total of 10 days from Dec 10 to Jan 10, with the pilots citing big waves or strong winds as reasons to abstain from their duties.

OLP has been calling for a private pilot service for years.