ENCRYPTION

The Computer and Communications Industry Association, a lobby group for Internet and telecoms firms including Google , Microsoft Corp and Facebook Inc, said the proposals were a concern.

"The bill is a setback for privacy rights and part of a worrisome trend towards more governmental surveillance in Europe while the United States is reforming its surveillance practices," CCIA Europe Director Christian Borggre said.

May said there would be no new ban on encryption, but in its guide to the bill, the Home office said there was an existing requirement on CSPs "to maintain permanent interception capabilities, including maintaining the ability to remove any encryption applied by the CSP".

The bill would also place explicit obligations on service providers to help intercept data and hack suspects' devices, which US experts said might defeat any encryption that remains, such as the end-to-end encryption on Apple's iMessages.

As well as being able to carry out bulk interception of communications data, the security services would be allowed to perform "equipment interference", whereby spies take over computers or smartphones to access their data.

Technology companies could be compelled to assist in that process. Even if they cannot be ordered to provide an update that would compromise equipment, said Kurt Opsahl, deputy executive director of the Electronic Frontier Foundation, they might be told not to issue an update that patches a security flaw being exploited by the government.

"Equipment interference is a big one, because that undermines trust in the products," said a US industry trade group's expert on the bill, asked to predict opposition from the likes of Apple, Facebook and Google. "If it makes you hesitate to update your iPhone software or use WhatsApp or Gmail, that's a big deal for them."

In a statement, Yahoo Inc said it was especially concerned that the law would extend to non-UK companies. It and other companies did not respond to questions as they digest the lengthy bill.