Microsoft and Google are to sue the US government to win the right to reveal more information about official requests for user data. The companies announced the lawsuit on Friday, escalating a legal battle over the Foreign Intelligence Surveillance Act (Fisa), the mechanism used by the National Security Agency (NSA) and other US government agencies to gather data about foreign internet users. Microsoft’s general counsel, Brad Smith, made the announcement in a corporate blog post which complained of the government’s “continued unwillingness” to let it publish information about Fisa requests. Each company filed a suit in June arguing that they should be allowed to state the details under the first amendment, which guarantees freedom of speech, and in the process defend corporate reputations battered by Edward Snowden’s revelations. Critics accused the companies of collaborating in the snooping.