The Union said in the strike notice the “increasing proliferation of anti-union practices in several Portuguese ports, which is extremely severe in the port of Leixões port and continues to be severe in the port of Caniçal,” was the reason for the strike.

António Mariano, the head of SEAL, told Lusa that it is “hard” to estimate the impact of the strike because the notice is on a national level, covering “every worker in all eight ports, unionised or not, along with those with insecure income.”

The stoppage includes ports of Leixões, Figueira da Foz, Lisbon, Setúbal, Sines, Caniçal, Praia da Vitória and Ponta Delgada.

According to the notice, the strike covers, “all overtime work, in other words, all the work that exceeds normal working hours or daily working hours, on business days, and all work on Saturdays, Sundays and holidays”.

The Union accuses port companies of “criminal behaviour” including “moral harassment from persecution to duress, from bribery to discrimination”, or “dismissal threats” and “salary blackmail”, to “turning workers against each other” and to prevent them from "free and conscious unionisation”.

These practices led to a manifesto being issued over a year ago after the union gathered testimonies of specific situations “which the port sector and labour authorities were given notice of,” but “these criminal situations are still unpunished,” according to SEAL.