A bipartisan group of Washington lawmakers sent letters Friday inviting Apple Inc. CEO Tim Cook and FBI Director James Comey to testify on their so-called debate over encryption technology. The letters come as the legal battle between the iPhone maker and the federal agency that began this week continues to escalate.

“Over the last year, with the growing availability and adoption of strong encryption measures by commercial technology providers, there has been an increasingly public and heated debate about the costs and benefits of encryption technologies, in particular, the impact these technologies have on law enforcement’s capabilities to investigate criminal conduct,” the U.S. House of Representatives Energy and Commerce Committee said in the letters.

Apple publicly opposed Tuesday a court order demanding it create custom technology that would allow the FBI to access the contents of an iPhone used by Syed Rizwan Farook, one of the perpetrators of the deadly terrorist attack in San Bernardino, California, Dec. 2. The U.S Justice Department responded Friday by filing a motion to compel the tech giant to comply with court orders.

“Rather than assist the effort to fully investigate a deadly terrorist attack by obeying this court’s order of February 16, 2016, Apple has responded by publicly repudiating that order,” the Justice Department said in its filing.

The House committee’s letters invite Apple and the FBI to “explain to Congress and the American people” their differences. The invitations by the House committee proposes a hearing at the “earliest opportunity.”

Apple executives said Friday they have attempted to help the FBI with its requests, but were unable to access the data on Farook’s phone after the Apple ID passcode associated with the device was changed, BuzzFeed reported. However, Apple refuses to create custom software to access the device, fearing it could set a dangerous precedent and that other users’ privacy could be at risk should the technology fall into the wrong hands.

Apple is widely expected to file an appeal against the court order sometime next week. A federal court date has been set for March 22, according to Reuters.