British consumer morale stayed in the doldrums in August as no amount of Olympic cheer seemed able to outweigh mounting worries about the economy, a survey by GfK NOP showed on Friday.

The poll's headline index held at -29, where it has been since May, disappointing economists' forecasts for a tick up to -27. Although the index is slightly higher than a year ago, it remains far below its average since 1974 of -9.

"Confidence has never been so low for so long - even during the dark days of the 2008-2009 recession," said Nick Moon, Managing Director of Social Research at GfK.

"Unlike last year's royal wedding, which boosted consumer confidence, there has been no spike to consumer sentiment following the Olympics."

Alternatively, he added, any uplift from the July 27-August 12 London Olympics might have been cancelled out by a grim economic outlook.

"Consumer confidence is trapped in a spiral of depression and it doesn't look like improving any time soon," Moon said.

The survey was conducted between August 3 and August 12 among a sample of 2,000 people, and was carried out by GfK NOP on behalf of the European Commission.

(Reporting by Olesya Dmitracova; Editing by Hugh Lawson)