UK consumer confidence climbed for a fourth consecutive month in August, a leading survey has suggested, in a sign that households are increasingly buying into the government's push to tackle the cost of living.

GfK's consumer confidence index rose to -14 this month, up three points from the net score recorded in July. The barometer, published monthly since 1974 and one of the longest-running gauges of its kind, is a net measure of optimists against pessimists, so the negative reading means downbeat respondents still outnumber upbeat ones even as the overall balance improves. The upward streak began in May, when Sir Keir Starmer's government stood on the brink of collapse following John Healey's resignation as defence secretary. Healey, now Chancellor and the minister leading the government's cost of living efforts, may enjoy the windfall of higher sentiment levels across the British public.

Neil Bellamy, insights director at GfK – the research company whose sentiment score is closely watched by economists – said the higher score may suggest that people had "greater faith" in Healey and Andy Burnham, although he cautioned it was "too soon to tell" whether confidence would continue on the upward trajectory.

"With inflation back on the rise – now at 2.9 per cent and the highest in four months – and with continued uncertainty in the Middle East and elsewhere, there are still many challenges ahead that will test the mettle of UK consumers," Bellamy said.

Across the survey's component measures, the highest score came in people's sentiment about their personal financial situation over the next 12 months, with a reading of four. That compares with -23 for respondents' mood on the general economic outlook over the same period. The survey of around 2,000 people also found that people were more confident about making major purchases, a component retailers track as a rough gauge of appetite for big-ticket spending. That matters beyond the shopping aisle because household consumption accounts for around three-fifths of UK economic output, so shifts in consumers' willingness to spend feed directly into the growth picture the new government has pledged to improve.

'Reduce retail costs' and boost consumer confidence

The data reflects similar bumps in consumer confidence recorded by the British Retail Consortium on Thursday.

Helen Dickinson, chief executive of the industry group for supermarkets, said Burnham and Healey were enjoying a "honeymoon boost driven by less pessimism about the outlook".

"The Budget will be the acid test of this government's real commitment to growth: if the government can reduce retail business costs, from energy bills to business rates, it will be ordinary households who feel the benefit," Dickinson said.

Burnham has said he would preside over a "cost of living government", with policies on reducing household energy bills and cutting taxes for pub landlords having already been announced. The Chancellor has also promised to offer businesses further "breathing space".

Devolution is expected to be the main growth lever used by the new government, offering local town leaders more powers over investment decisions.