Consumer confidence rose at the highest rate in almost two decades during May as the royal wedding and sunny weather heralded a return of the feelgood factor.

However it remains too unclear whether the shift marks a deeper return to optimism or is simply a spark in the gloom.

Gfk NOP’s Consumer Confidence Index climbed 10 points to -21 during May – the second largest rise ever recorded and the steepest monthly increase since May 2003.

All five measures used in the index were up, including attitudes to major purchases which rose five points and confidence in the general economic outlook, which was ahead 15 points.

GFK NOP social research managing director Nick Moon described the increased level of confidence as “almost unprecedented” but struck a note of caution.

He said: “This is just one month’s figure and it is far too early to know whether this could be the start of an upward trend. We are improving from a rock-bottom position and consumer confidence is still deeply in the negative.

“Whether the current spring in consumers’ steps is due to the feelgood factor of the royal wedding and a double-whammy of sunny bank holidays, or to the recent let-up in negative reporting about the state of the economy, we are not out of the woods.”