Spain's two main unions have called for a general strike on 29 March to protest against changes to labour laws.
They are unhappy with new rules designed to make it simpler and cheaper for employers to fire staff.
A spokesman for the Workers General Union (UGT), Candido Mendez called the strike "fair and necessary".
But Deputy Prime Minister Soraya Saenz de Santamaria said strikes were "not the answer in very hard times for citizens".
Spain has the highest unemployment rate in the EU at 23% and this figure is expected to rise further.
But the government hopes the reforms will encourage businesses to take on more employees.
There is concern that the Spanish economy is heading back into recession after it contracted at the end of last year.