GCHQ's involvement in the mass collection of citizens' data was revealed when former U.S. National Security Agency contractor Edward Snowden leaked explosive top secret documents to the media in 2013. A steady stream of those files has continued to leak.
Snowden's revelations sparked a fierce debate in Britain and the U.S. about the legality of the activities carried out by the countries' spy agencies. In February, the U.K.'s Investigatory Powers Tribunal ruled that the laws around the sharing of electronic communications between GCHQ and the NSA collected as part of the mass surveillance programs of both agencies breaches human rights regulations.
But another inquiry in March by the U.K. parliament's Intelligence and Security Committee (ISC) found that the bulk collection of communications by GCHQ "do not seem to circumvent the law" but are "unnecessarily complicated" and "lacks transparency".
The U.K. is looking to strengthen the powers of security agencies through a new communications bill - labelled by critics as as the "snooper's charter" - which would require internet and mobile phone companies to keep data such as a call and text message history for a year.
In the U.S., the Patriot Act which was passed in the wake of the September 11 terrorist attacks in 2001 and allows the collection of Americans' phone data, expired on Sunday. But many of the rules allowing this surveillance could be retained in the Freedom Act which will be voted on in Senate on Tuesday.
But two British companies – privacy app ind.ie and software company Eris Industries – have said they would leave the country because of GCHQ's mass surveillance and the proposed extension of powers in the latest bill.
However, Martin denied that GCHQ's policies were driving firms out of the U.K, when asked about the topic. Skirting around the question, Martin referred to an answer given by BT Group chairman Mike Rake last year which was supportive of the intelligence agency.
"It was put to Sir Mike Rake...whether he thought the government and GCHQ in particular...was having any impact on U.K. tech and the answer was no," GCHQ's cyber chief said.