Portugal's main opposition party on Thursday took a new law extending civil servants' working hours to the country's highest court, in a fresh challenge against the tough austerity measures imposed by the government in exchange for bailout funds.
The law requires civil servants to extend their working hours from 35 to 40 a week.
The government hopes that it will translate to 204 million euros in savings by the end of next year.
Lusa news agency said 37 MPs of the main opposition Socialist party had challenged the legality of the measure, arguing that the extension should be accompanied by pay rises.
Meanwhile, the government adopted another austerity measure on Thursday, which would hit ex-civil servants who are receiving pensions of more than 600 euros a month with a 10 percent cut.
That measure is widely expected to also end up before the constitutional court.
A series of austerity measures introduced by the Portuguese government in exchange for a 78-billion-euro bailout put up by the International Monetary Fund and European Union has proved unpopular in the country, and has sparked several legal challenges.
On August 29, the court struck down a key provision of the government's latest austerity programme, throwing the bailout into question.
In that ruling, a measure that could lead to job losses for civil servants was found to flout the country's "job safety guarantee" and therefore unconstitutional.
In April, the court also ruled against several measures in the government's 2013 budget, including a controversial slashing of bonuses for civil servants and pensioners.
The government narrowly survived a political crisis in July when key ministers resigned over widespread public resistance to further austerity policies as part of the bailout.