RPI

However, rates on non-draught products, such as wine and spirits, will rise by the higher RPI measure of inflation.

Tax on non-draught alcoholic drinks will increase by the higher RPI measure of inflation, but tax on draught drinks will be cut by 1.7%.

But one of them - known as Plan 2 - charges interest based on RPI in March, plus up to 3%.

For example, in July RPI inflation was 3.6% compared with CPI inflation of 2.2%.

The union used a measure of inflation known as RPI, which includes housing costs, as the basis for its pay claim.