Professor David Miles of the OBR has told MPs that the freeze on income tax thresholds is one of the three main reasons household disposable income has barely grown this decade, City AM reports.
According to City AM, he told the Treasury Committee that the other two factors were weak growth in GDP per capita since the financial crisis and the recent rise in energy prices.
"It's increasing the average tax take out of people's income that comes straight out of disposable income."
City AM reports that he said the freeze means the Treasury takes billions of pounds more than it would if thresholds rose with inflation. That fits the OBR's own estimate that the freeze raises £58bn by 2030-31.
Miles had already described the outlook for living standards as a "pretty grim picture". His remarks to the committee have not been independently checked against a transcript.