The Spanish parliament on Tuesday gave the green light to an emergency procedure allowing for the rapid approval of a constitutional reform aimed at limiting budget deficits, DPA reported.
The procedure, which was approved on a 319-17 vote, will make it possible to approve the reform in the coming week.
The governing Socialists and the opposition conservatives have struck a deal on the reform, which will introduce a budget deficit cap into the constitution, partly in an attempt to calm financial markets over Spain's economic stability.
The constitution would not put numbers on how much debt the state, regions and municipalities are allowed to have, but a subsequent law is expected to set the limit at 0.4 per cent of gross domestic product from 2020 onwards.
Prime Minister Jose Luis Rodriguez Zapatero said the reform was "very important for Spain at this time."
However, trade unions, the far left and even some Socialists have criticized the reform as impoverishing citizens by cutting social spending.
Spain's two main trade union confederations, UGT and CCOO, on Monday called a demonstration in Madrid for September 6 against the reform, accusing the government of being "a prisoner of markets."
Thousands of followers of the anti-unemployment Indignant Ones protest movement also demonstrated against the reform on Sunday, criticizing the procedure as undemocratic and calling for a referendum.
Spain's 20-per-cent unemployment is the highest in the European Union. There has been concern about the financial stability of the country, which is trying to cut its budget deficit from 9.2 per cent in 2010 to 6 per cent this year.