Federal law enforcement officials are pressing their concerns about encryption before Congress, where they will argue to senators on Wednesday that the right to privacy is not absolute and must be weighed against public safety interests.

The testimony by FBI Director James Comey and Deputy Attorney General Sally Yates, the No. 2 official at the Justice Department, adds to an ongoing and high-stakes dispute between the Obama administration and some of the world’s most influential technology companies.

At issue is encryption technology in phones and computers that Silicon Valley companies say offers customers’ invaluable security in their communications and protection from hackers and corporate spies. But law enforcement officials say that same technology has made it harder for them, even with a warrant, to monitor and intercept messages shared by criminal suspects. They say that concern is especially acute at a time when the Islamic State has used social media to reach followers in the United States, then moved the conversation to encrypted platforms.

“The current public debate about how to strike the careful balance between privacy rights and public safety has at times been a challenging and highly charged discussion,” Yates will tell members of the Senate Judiciary Committee, according to excerpts of her remarks. “I believe that we have to protect the privacy of our citizens and the safety of the internet.

“But those interests are not absolute. And they have to be balanced against the risks we face from creating warrant-proof zones of communication,” she will say.

Technology companies, however, have pushed back strongly against the government’s position, calling the concerns overblown and vowing to steadfastly protect their customers’ privacy. Among other arguments, they say that any “key” that could give law enforcement access to encrypted devices could presumably be exploited by hackers and criminals too.

In a speech last month, Apple CEO Tim Cook said the company would not waver in offering encryption tools to customers and said weakening encryption would have a “chilling effect on our First Amendment rights and undermines our country’s founding principles,” according to the website techcrunch.com. An Apple spokesman confirmed the remarks to The Associated Press.

In a May letter to the White House, a coalition of companies argued that strong encryption protects against “innumerable” threats and urged the government to “reject any proposal that U.S. companies deliberately weaken the security of their products,”

“We request that the White House instead focus on developing policies that will promote rather than undermine the wide adoption of strong encryption technology. Such policies will in turn help to promote and protect cybersecurity, economic growth, and human rights, both here and abroad,” the letter said.

(AP)