The “national” action is to take place from 5pm, with a march from Praça do Comércio, downtown, to parliament, and is organised by the standing coordinating committee of the unions and associations representings police and other internal security forces.

César Nogueira, the president of the APG, which represents members of the National Republican Guard (GNR) and national secretary of the coordinating committee, told Lusa agency that the demonstration "is open to all police" and so members of other organisations were also likely to take part.

Nogueira said that police were angered at the fact that the draft state budget for 2019, which is now being debated in parliament, does not foresee any improvement in career progression for police, or other measures to fully compensate them.

It does not, he said, provide for "visible investments in human and material resources, boosting ageing police institutions that are working at their limits."

The Socialist government, he said, “has promised a lot” but, with the parliament nearing its end, “nothing concrete" had emerged.

In the case of the GNR, Nogueira said, poor management and a lack of investment meant that many obsolete vehicles and computers are still in service.

Paulo Rodrigues, the president of the ASPP, which represents officers in the PSP urban police force, cited a decision by the Supreme Administrative Court that ruled that cuts made in various benefits were illegal, including supplements for beat service and shift work in holiday periods. The court also ruled that the supplicants should be paid retroactively for the period since 2011, when the benefits were cut.

In the Foreigners and Borders Service (SEF), inspectors are complaining above all about a lack of staff and resources, namely in computers, according to the SCIF union