But in the British filing, and in an interview on “60 Minutes” on Sunday, Apple’s chief executive, Tim Cook, argued that politicians calling for such access do not understand the damage they would cause.

So far, Mr. Cook still has a partial ally in President Obama. The White House determined in October that, despite a recommendation from the F.B.I. to put forward legislation requiring access to encrypted communications, it would not seek legal changes. That rankled the F.B.I. director, James B. Comey, who has long warned about the “going dark” problem, and offered up evidence a week ago that an attack in Texas this year had been plotted over encrypted text messages, which he said investigators still could not crack.

Apple pushed back on Mr. Comey’s arguments in its submission to the British government. “Some would portray this as an all-or-nothing proposition for law enforcement,” it wrote. “Nothing could be further from the truth. Law enforcement today has access to more data — data which they can use to prevent terrorist attacks, solve crimes and help bring perpetrators to justice — than ever before in the history of our world.”

That data, many experts say, includes phone “metadata” about who is calling whom, GPS coordinates for individuals, and access to unencrypted data stored on so-called cloud services. But the arguments in Britain and the United States have focused largely on systems designed by Apple and its competitors, including Google and Microsoft, that automatically encrypt data exchanges, and put the keys to those communications into the hands of the users, not the companies.

Apple contended that if Britain went ahead with its legal changes, the company, and its competitors, may find themselves violating American laws to comply with British law — or vice versa. “This would immobilize substantial portions of the tech sector and spark serious international conflicts,” it argued.