Apple has said that a proposed encryption bill in the U.K. Parliament would send the tech sector into chaos.
The Investigatory Powers Bill would give British law enforcement increased powers to collect people's private communications, and it would require foreign companies to comply with U.K. warrants.
Tech companies and lawmakers have differing views about how to read the proposal.
The government has said tech companies would not be required to rewrite any of their code to make it easier for officials to access people's private communications.
But Apple (Tech30) and several other companies say they believe the bill would require them to build backdoors that would let both law enforcement and hackers snoop on customers' private conversations. ,
In written testimony to Parliament, Apple said lawmakers are trying to set off a nuke to kill a fly.
"The bill threatens to hurt law-abiding citizens in its effort to combat the few bad actors who have a variety of ways to carry out their attacks," Apple said in its letter. "The creation of backdoors and intercept capabilities would weaken the protections built into Apple products and endanger all our customers. A key left under the doormat would not just be there for the good guys. The bad guys would find it too."
Apple and key British lawmakers did not respond to requests for comment.
Apple also reasserted its previous stance -- backed up by mathematicians -- that there is no way to build a system that would protect the private conversations of innocent people but send criminals' texts and messages to law enforcement.
The way the Investigatory Powers Bill treats warrants has become another key issue for Apple and its rivals. If the United Kingdom uses a warrant to force Apple to turn over customer data, it could be viewed as a data hack in the United States.
"The bill would attempt to force non-U.K. companies to take actions that violate the laws of their home countries," Apple said. "This would immobilize substantial portions of the tech sector and spark serious international conflicts ... paralyzing multinational corporations."
A Microsoft spokesman said "the legislation must avoid conflicts with the laws of other nations and contribute to a system where likeminded governments work together, not in competition, to keep people more secure."
The U.K. government released a revised version of the bill in November, and it will be debated in the New Year.
Proponents say the bill has plenty of safeguards, including judicial oversight, to ensure transparency and citizens' privacy. They say the bill is necessary to counteract threats of terrorism.
"The Government is committed to ensuring law enforcement and the security and intelligence agencies have the powers they need to keep us safe in the face of an evolving threat and an increasingly complicated communications environment," U.K. Home Secretary Theresa May said in her introduction to the bill.
The bill is likely to pass, as the Conservative party that introduced the legislation have a clear majority. What remains to be determined is what changes will be made to the bill before its language is finalized.
-- CNNMoney's Jim Boulden contributed to this report.