Consumer confidence reached its highest level in nine years during May and has soared over the last year.

Researcher Gfk’s Consumer Confidence Index recorded a three-point improvement during the month, bringing the measurement to zero after almost a decade in negative territory.

All measures, including people’s confidence in their personal financial situation and their attitude to big-ticket purchases, advanced over the month.

However, Gfk managing director of social research Nick Moon said that “the real driver of the increase is people’s assessment of the general economic climate”.

He observed: “A rise of three points in the index in a month is itself a significant change but what matters more, psychologically at least, is that the Index has left negative territory for the first time in over nine years.

“It is not actually positive but this is the first time it has reached zero since April 2005.”

Over the last 14 months since April 2013 the Index has risen a “remarkable” 27 points– the biggest gain since June 1977.