A final decision on the strikes, which would fall on a Tuesday and a Thursday, respectively, will be made next week Tuesday (25 July).
In a statement, the Fectrans transport and communications union said: “The Socialist government and the administration of Lisbon Metro, instead of endeavouring to solve the serious problems inherited from the previous government, have opted instead to instil an atmosphere of confrontation by means of a unilateral amendment to the rules governing the provision of work and hours.”
“What is actually needed is that more workers are admitted, the company is supplied with the appropriate rolling stock, the conditions at stations are improved, and that workers, who every day do what they can to, under current conditions, have a public service with the minimum standards of quality, are respected”, it argued.
Newspaper Público reports maintenance and track workers will also be joining the action.
The strike announcement was made the night before Arroios station was closed for renovation works, which are expected to take over a year to complete.
The central Lisbon station, on the city’s main Green Line, is to close for over a year, causing local shopkeepers to vent their anger, saying they had been poorly informed about goings-on.
Arroios metro station closed on Wednesday for modernisation works that are expected to last until 2019.
Local shopkeepers have complained that many clients will now not visit them and although the works were obviously needed, they were not properly informed about proceedings.