Retail sales in Britain, a key component of the economy, rose by a solid if unspectacular 0.3 percent in July from the month before as consumers remain constrained by falling real incomes.

The rate of increase reported by the Office for National Statistics was unchanged from June’s rise, which was downwardly revised from 0.6 percent. However, it was slightly ahead of market expectations for a 0.2 percent rise.

The statistics agency said Thursday that strong food sales were behind the monthly increase as all the other main sectors posted falls.

Senior statistician Ole Black said trends in growth in different sectors are “proving quite volatile.”

Retail sales have been sluggish this year as consumers have become cautious amid a rise in consumer prices. That’s evident in the fact that retail sales in the three months to July were up only 0.6 percent from the previous three-month period, against the 1.5 percent recorded in…