The first planned strike in public education at all levels of the system from primary school through to university took place in Spain on Thursday.
The strike, which has been organized by the State Platform for Public Education, protests spending cuts in the sector and a new law to improve the quality of education, known as the 'Wert Law' after Education Minister Jose Ignacio Wert, which could well be approved on Friday.
Opponents of the Wert Law consider it "an abuse that will generate discrimination in the sector," pointing out it does away with subjects such as citizenship and that it would affect the use of the Catalan language.
The law also offers public finance for schools which want to segregate students by sex, making single sex schools and classes much easier.
The strike will affect around 5.5 million students and teachers at the non-university level and around 1.4 million university students and 100,000 professors.
Thursday's strike forms part of a series of mobilizations which include information sessions and lock-ins in schools and universities which began in April. Unions refuse to rule out further action in the coming months.
Primary and infant schools in Madrid remained open, while in Catalonia there will be one teacher for every four classes. In nursery schools, 30 percent of staff will be on duty.
Thursday's strike comes just 48 hours after over 70,000 public health service workers in Madrid carried out the first in a series of one-day strikes against plans to privatize six public hospitals and 27 health centers in the region.