Tech giant requests freedom to share information with customers after revelations of data co-operation between NSA and Microsoft

Microsoft has written to the US attorney general, Eric Holder, calling on him to "personally take action" to permit the software giant and others to share more information about the way they handle national security requests for customer data.

The move comes after the Guardian published details of the extent of the co-operation between Microsoft and the National Security Agency (NSA), revealed in documents obtained by whistleblower Edward Snowden.

"We believe the US constitution guarantees our freedom to share more information with the public, yet the government is stopping us," Microsoft said in a blogpost. "For example, government lawyers have yet to respond to the petition we filed in court on June 19, seeking permission to publish the volume of national security requests we have received. We hope the attorney general can step in to change this situation."

Microsoft claimed there were "significant inaccuracies in the interpretations of leaked government documents reported in the media last week." It said: "We have asked the government again for permission to discuss the issues raised by these new documents, and our request was denied by government lawyers."

According to NSA documents seen by the Guardian, the US intelligence services claimed to have worked closely with Microsoft to allow users' communications to be intercepted and to circumvent the company's own encryption.

In Microsoft's latest statement, the company is at pains to point out that it did not give the NSA or any other US agency "direct" access to its customers data – a claim that was not made by the Guardian last week but was made in subsequent media reports. The NSA also claimed "direct access" in other documents published earlier by the Guardian and the Washington Post.

Microsoft, Google, Apple and others mentioned in those NSA documents have consistently denied any "direct" access.

In the company's latest posting, Brad Smith, Microsoft's general counsel and executive vice-president of legal and corporate affairs, wrote: "Microsoft does not provide any government with direct and unfettered access to our customer's data. Microsoft only pulls and then provides the specific data mandated by the relevant legal demand.

"If a government wants customer data – including for national security purposes – it needs to follow applicable legal process, meaning it must serve us with a court order for content or subpoena for account information."

Smith said Microsoft does not provide any government agency with the ability to break its encryption, nor does it provide the government with the encryption keys.

The statement comes after Yahoo successfully challenged a government ban on the publication of details of a key 2008 court case. Yahoo appealed to the Fisa court, which oversees the NSA's surveillance operations, to let it publish details of its fight with the NSA in a request that has been seen as a test case for further government bids for information from Yahoo's customers.

The court has ruled it will unseal documents related to Yahoo's objection to the secretive Prism surveillance programme. The court retained the right to redact "properly classified information".

"Once those documents are made public, we believe they will contribute constructively to the ongoing public discussion around online privacy," Yahoo said in a statement.

Yahoo and Microsoft join Google, Facebook, Apple and others in putting pressure on the government to be more transparent about its surveillance programmes.

Separately, the pressure group the Electronic Freedom Foundation (EFF) has filed a lawsuit on behalf of 19 groups including Greenpeace, Human Rights Watch and the First Unitarian Church of Los Angeles, alleging that the mass collection of phone records under Prism violates Americans' constitutional rights.

"The first amendment protects the freedom to associate and express political views as a group, but the NSA's mass, untargeted collection of Americans' phone records violates that right by giving the government a dramatically detailed picture into our associational ties," said EFF legal director Cindy Cohn.

"Who we call, how often we call them, and how long we speak shows the government what groups we belong to or associate with, which political issues concern us, and our religious affiliation. Exposing this information – especially in a massive, untargeted way over a long period of time – violates the constitution and the basic first amendment tests that have been in place for over 50 years."