Apple has raised concerns about the UK's draft Investigatory Powers Bill.
The proposed law aims to overhaul rules governing the way the authorities can access people's communications.
The US-based firm has passed on its thoughts to a parliamentary committee scrutinising the legislation.
It focuses on three issues: encryption, the possibility of having to hack its own products, and the precedent it would set by agreeing to comply with UK-issued warrants.
However, a spokesman for Microsoft commented: "The legislation must avoid conflicts with the laws of other nations and contribute to a system where like-minded governments work together, not in competition, to keep people more secure.
We appreciate the government's willingness to engage in an open debate and will continue to advocate for a system that is workable on a global basis."
