The Office for National Statistics is to revise the way it calculates its much criticised official retail sales figures.

The Government’s official statistical body said the net impact of the changes will be to revise down its estimates of sales volumes. There will be no impact on the assessment of sales values. Retailers have frequently attacked the ONS figures for overstating the level of sales.

The changes, which introduce an internationally recognised statistical technique known as chain-linking, have been developed following consultation with the Bank of England and the Treasury. They will take effect from the figures to be published next Thursday.