The new estimate is the result of a change in methods of determining growth

Britain is officially better off than had been believed. According to the Office for National Statistics the economy is about £26 billion bigger than had been estimated.

The UK is the world’s fifth-largest economy, with annual output worth £2.2 trillion last year, the International Monetary Fund said in April.

The revised data puts the average GDP growth from 1997 to 2016 at about 0.1 of a percentage point higher than the old estimate of 2.1 per cent. It means that over the period, the economy was 1.3 per cent larger than had been calculated.

The upgrade by the government’s statistics office was largely because of cuts in the estimates for how long assets such as buildings, computers and machinery can be used, the ONS said.