With interest rates held at a record low, the average Scottish household in July had £149 a week of “discretionary income” – money remaining after subtracting taxes and normal expenses. That is

6.2% higher than last year but still behind the average UK discretionary income of £163.

While some costs have fallen, the latest Income Tracker report for retail giant Asda found families were still faced with increases in transport and energy costs.

Food and drink inflation is at its lowest since September 2007 but transport costs rose for six months in succession as petrol prices hit their highest level since October 2008, according to the report.

Gross income rose by £8 a week in Scotland in July 2009 compared with 2008.

Andy Bond, Asda president and chief executive, welcomed the increase in household income, but said people might be reluctant to spend it.

“This is obviously a positive trend for consumers who have been feeling the pinch in the credit crunch,” he said.

“As we’ve seen over the past year, even a small movement in discretionary spend can make a big difference to a household budget. However, how people choose to spend their money is still dictated by sentiment, and consumers remain fundamentally cautious about the future.”

Mortgage interest payments stood 45.5% lower in July 2009 compared with a year ago, as the Bank of England keeps interest rates on hold at the record low of 0.5%. Overall essential spending was £5 a week lower in July 2009, compared with the year before.

Charles Davis, an economist at the Centre for Economics and Business Research who compiled the report for Asda, said: “Inflation is expected to fall further as the economy runs below capacity, boosting spending power.

“However, spending power could also come under some pressure from the global ­economic recovery pushing commodity prices higher and the weak labour market ­outlook.”