UK consumer confidence slumped to its longest decline for three years after falling for a third straight month in December.

The GfK UK Consumer Confidence Index fell to -13 in December from -12 in November, despite an improving economic outlook that has caused confidence to rise from -29 in December 2012.

However, real income growth remains low because average wages are not rising as quickly as product prices.

The major purchase index was down four to -17 which will be a blow to big-ticket retailers, although this was an improvement from -27 a year ago.

Consumers were also negative about the outlook for the economy in the year ahead, down three points from November at -4. However, that compared with a much more pessimistic -31 in December 2012.

GfK NOP Social Research managing director Nick Moon said: “The explanation for the last quarter of declining confidence most likely results from people’s sense of how well – or rather badly – off they personally feel.”