The Office for National Statistics said its new method, due to be introduced to the official inflation data in March, would have raised the average annual increase in rental prices to 2.8% from 2.1% between January 2016 and October 2023.

This in turn would have pushed up the average annual increase in the consumer price index to 3.5% from 3.4%.

"The new estimates utilise improved methodology, allowing better use of the previously received data, and doubling the number of rental prices used to produce the statistics to around 500,000 per year," the ONS said in a statement.

The ONS also published new estimates of second-hand car prices, based on data from car sales portal Auto Trader, that will vastly increase the number of prices used to form the data.

However, it said the new methodology for car prices would have had no impact on consumer prices to one decimal place in past years.

(Reporting by Andy Bruce, Editing by Paul Sandle)