MORALE among staff at GCHQ is said to have been galvanised by allegations their snooping powers have exceeded the limits of the law.
Leaked information suggested the eavesdropping agency taps into masses of internet and telephone communications secretly.
It was one of a string of disclosures by US whistle blower Edward Snowden.
Julia MacGregor, chair of the Government Communications Group, which represents more than half of the 5,000 staff at the Benhall doughnut, said the claims had been difficult. But she denied there was any case of employees operating as "mavericks".
"The mood among staff is one of hurt and frustration that there are implications being made," she said. "I wouldn't say there is a siege mentality, but because of the nature of the work we do we don't have a right of reply so of course it is frustrating.
"But whilst the allegations have not been good for morale, in a way it has brought staff together."
As a result of the claims, an internal electronic message board entitled Proud to Work for GCHQ has been launched, where staff can leave comments to reflect their pride in their efforts to protect national security.