The law, championed by the ruling Popular Party (PP) and fiercely opposed by rights groups and left-wing opposition, will be passed on Thursday, in what has been labelled "a bad day for democracy" according to Greenpeace, whose members staged a protest outside the Spanish parliament.
Dressed in green t-shirts and wearing green gags, members of the environmental organization protested outside of Spain's lower parliament on Thursday morning against the passing of the country’s tough new Citizen Security Law, dubbed the Ley Mordaza, or Gagging Law by critics.
Along with the Citizen Security Law, the Spanish government is on Thursday set to approve reforms to the country’s penal code and a new anti-jihadist law, despite criticism from the United Nations and the Council of Europe.
The trio of new regulations will criminalize protests, with fines of up to €600,000 for unauthorized protests outside buildings "which provide basic services to the community", sparking accusations of the government preventing free speech.
Permanent prison sentences in particularly serious cases will also be introduced, which opposition parties have called "inhumane" and "unconstitutional" according to Spanish daily, 20 minutos.
A particularly controversial aspect of the new law is the legalization of the sending back of immigrants found on the border of Spain’s North African enclaves of Ceuta and Melilla "to prevent their illegal entry into Spain".
The United Nations and Council of Europe have already warned Spain that legalizing the sending back of immigrants would contradict the European Court of Human Rights, which prohibits collective expulsions.
A poster protesting against the new gagging law says "The Gagging Law - why do they want to shut us up?"
According to a Metroscopia poll conducted in December 2014, 82 percent of Spaniards are in favour of softening the laws, or scrapping them altogether.
The law has attracted numerous protests throughout Spain in recent months, including a large gathering in Madrid's central square, Sol, on February 14th 2015.
The tough new regulations are set to come into law on July 1st, 2015.
"If you want to protest, you'd better get to an ATM."