Legislation introduced by French Prime Minister Manuel Valls that seeks to broaden the surveillance powers of French intelligence services — particularly the monitoring of online activities — has been met with criticism from those who fear the proposed law could threaten civil liberties and lead to excessive and intrusive surveillance of civilians.

Speaking at a press conference Thursday, Valls said he hoped the legislation would be passed soon, pending a debate in the country's National Assembly. The prime minister said the bill authorizes,"Legal means of action but no exceptional measures or widespread surveillance of civilians."

According to recent figures,1,900 French nationals are currently affiliated with jihadist networks, either in France or abroad. Valls said 770 of these radicalized French citizens have already fought or are still fighting alongside militants in Iraq, Syria, and other countries.

Valls stressed the need for new anti-terror legislation, pointing out that the country's current surveillance law was drafted in 1991, long before the rise of the internet and the widespread use of cellphones. Speaking to journalists Thursday, he said that aspects of the current law that have already proven useful would be preserved.

Many politicians have welcomed the proposal, including conservative UMP party chief Nicolas Sarkozy, who told French television channel TF1 that his party would vote in favor of the bill as long as "its essence wasn't modified during the parliamentary debate."

Under the latest proposal, French intelligence services would be authorized to capture images and data while spying on private telephone and email communications. Government agents would be allowed to hide all kinds of surveillance gadgets — including video cameras and microphones — in suspects' homes. They would also be able to place tracking devices on vehicles, and equip computers with software that records every keystroke made by users.

Any monitoring would need to be authorized by a new administrative authority called the National Commission for the Control of Intelligence Technical Control (CNCTR). All surveillance operations would be placed under the direct authority of the prime minister and would no longer require a court order.

In January, the French government was forced to acknowledge intelligence failings after it emerged that the Kouachi brothers, who carried out the deadly Charlie Hebdo attacks in Paris, had been under surveillance for years. The monitoring of the brothers stopped in summer 2014 when the renewal of a four-month surveillance authorization was forfeited due to insufficient evidence.

The potential for French authorities to circumvent the courts has caused grave concern among civil liberties advocates and members of the legal profession. Lawyers from the Paris bar released a statement calling for "a unique framework to supervise the monitoring," and for "the intervention of a judge to oversee, authorize and sanction" any surveillance operations.

The French data protection agency (CNIL) added its voice to the chorus of criticism and expressed concern that doctors, journalists, and attorneys would not be exempt from the broadened monitoring.

The bill also sanctions the use of IMSI catchers, a device used to eavesdrop on mobile phone traffic and track the movements of cell phone users. The IMSI catchers will, however, require authorization from a judge.

IMSI catchers are illegal in some countries due to privacy concerns. The devices pose as a cell phone tower and trick cell phones into connecting, collecting not only their data, but also the data of nearby mobile devices.

Despite reassurances from the government that the use of IMSI catchers would be restricted, the CNIL has warned of potential violations associated with the devices, which it says, "enable the systematic and automatic gathering of data associated with people who have no link, or a purely geographical link, to the person that is being monitored."

In February, French Interior Minister Bernard Cazeneuve traveled to Silicon Valley to meet with representatives from Apple, Google, Facebook, Twitter, and Microsoft to lay the foundations for potential future collaboration on France's counterterrorism agenda.

According to the new legislation, these companies will be tasked with providing authorities with a suspects' connection data "in real time." Internet providers will "automatically detect" suspicious connection data using algorithms, and will alert the French authorities to any suspect online activity.

Benoît Thieulin, president of the French digital council, told French daily Libération that the new measure "changes the very nature of intelligence by placing algorithms at the heart of decision-making."

French intelligence agents will be able to cite a number of justifications for obtaining authorization to use the new spying methods, including "countering terrorism" and "national security." The list of "public interest" justifications named in the bill also includes "the protection of France's economic interests" and "the prevention of collective violence that could seriously disrupt the public peace."

"The scope of application is extremely wide," Laurence Blisson, a member of a left-wing judges union, told Libération. "The prevention of violence, for example, could affect political rallies."

Éric Dénécé, director of the independent think tank French Center for Intelligence Research, told VICE News that he thinks the new law will be "efficient."

"It's not an intelligence law, but a law on the counterterrorism methods granted to internal security services — mainly, law enforcement" he said, adding that the law would not affect external intelligence agencies.

"You mustn't give too much credence to the myth of possible violations," he added, addressing criticisms of the proposal.

Asked how the law compares to the sweeping surveillance conducted by the NSA in the United States, Dénécé said, "The US is not an example that should be followed — in fact, you could call it an example of counter-democracy." In France, he said, "We are light years away from having the human resources to undertake this type of [widespread] surveillance."

Dénécé's main concern is that the new powers will not be subject to "time limits," such as a renewable one-year term of use.

Bertrand Warufsel, a professor at Université Lille II and a practicing attorney in Paris, told VICE News that the new bill will provide an effective regulatory framework for counterterrorism intelligence.

"From now on, the new intelligence methods, such as audio monitoring, tracking or computer penetration, will also be subject to an independent body made of up judges and lawmakers," Warufsel said. "This will be an undeniable improvement on the current situation, where intelligence services work without any safety net, and without a legal framework."

France's parliament will begin debating the bill on April 13.

Follow Mélodie Bouchaud on Twitter: @meloboucho

VICE News reporter Pierre Longeray contributed to this article.