Speaking to journalists outside Lisbon's São José Hospital, the union's president, José Carlos Martins, said that 90.3 percent of those called out had been on strike, while at Porto's São João Hospital 79 percent of had taken action. He promised nationwide figures later in the day.

The union's main demand is that more staff be hired to cope with the impact of the shift to a working week of 35 hours, from 40 hours.

According to Martins, the government on Monday pledged to conclude the authorisations for hospitals to hire some 2,000 more nursing staff, but he said that this was not sufficient and came very late in the day. The was the agreed shift to the 35-hour week had been handled had evidenced "incompetence" and a "lamentable political management", he said, noting that it has been known since October last year that the new rules would apply from 1 July.

Even if the hiring process starts now, he argued, the nurses will still have to apply to individual services, and will come on stream in the middle of the holiday period, when there are fewer colleagues around to help them settle in.

In addition, they are to be hired on fixed-term contracts, despite carrying out the duties of permanent staff.