LONDON (REUTERS) - British lawmakers will question the editor of the Guardian newspaper next month over publishing intelligence files from the United States spy agency contractor Edward Snowden after warnings from security chiefs that the leaks damaged UK national security.

Alan Rusbridger will appear before the House of Commons home affairs select committee, the Guardian said. "Alan has been invited to give evidence to the ... committee and looks forward to appearing next month," a spokeswoman said.

Disclosures about the activities of Britain's GCHQ eavesdropping agency and its close cooperation with the U.S.

National Security Agency, have embarrassed Prime Minister David Cameron and angered lawmakers in his ruling Conservative party who say they have compromised national security.

Civil liberties groups say the files have shown the need for more effective controls over intelligence gathering but spy chiefs have been highly critical about their publication.

"They've put our operations at risk," John Sawers, the head of MI6, Britain's foreign intelligence service, told a parliamentary committee earlier this week. "It's clear that our adversaries are rubbing their hands with glee - Al Qaeda is lapping it up," he said.

Last month, Cameron threatened to act to stop newspapers publishing the leaks.

Mr Rusbridger, a former Washington editor for the London Daily News, has defended the Guardian's role, saying it has provoked a debate about the extent of intelligence activities, which lawmakers had failed to do.