Scores of Spanish police officers and their supporters marched on the streets of Madrid on Saturday protesting against the government plans to improve a controversial security law known by critics as the ‘gag law’.

The Citizens Security Law was passed by the previous conservative government in 2015. Critics of the law have been saying for years that it gave too much power to security forces to detriment of civil liberties.

However, powerful police unions are of the opinion that the proposed changes to the law will make their job more difficult.

A new version of the law is being sponsored by the small Basque Nationalist Party or PNV. The newer version of the controversial law earned the support of Spain’s governing left-wing coalition.

Meanwhile, Amnesty International and Spain’s Ombudsman Office called for the law to be tweaked.

In the current scenario, while the tweak would negate some of the most contentious parts of the current law, the proposed law could still undergo changes during negotiations in the parliament’s lower chamber.

The contentious parts of the law include the article that banned holding protests in the immediate vicinity of Congress or Senate buildings and the article that allowed border guards to push back migrants who had crossed the frontier.

A new change that is supported by the government is the allowance for spontaneous protests that now commonly arise from a quick organization of a march.

Currently, organisers of protests or marches have to inform the authorities beforehand.

Police unions are against other planned modifications, above all one to remove a requirement for citizens to request permission from authorities before filming and publishing a video of officers at work.

Last year, Spain’s Constitutional Court ruled that such a requirement for previous approval was unconstitutional.

But police fear that could make their officers easy to identify and thus put them at risk for reprisals.

“The reform that the government is preparing will only benefit violent protesters and criminals,” Associated Press quoted Pablo Pérez, spokesperson of the JUPOL union for Spain’s National Police as saying.

“It puts citizens and especially police officers in serious danger because it ties our hands and feet when facing violence,” Perez added.

Right-wing opposition parties backed the police protesters. Both the far-right Vox party and the Popular Party that passed the original security law while in power sent their leaders to the rally.

Socialist Party spokesman Felipe Sicilia said that government wants to “adapt the law to a new era” and rewrite it so as to “reduce doubts about the right to gather in public and to protest.”

“This law is to improve our way of handling public security,” Sicilia said. “And, of course, it means to protect our members of the security forces so that they can work in a professional manner and with legal guarantees.”

(With inputs from Associated Press)