According to new figures, people in professionally classed occupations such as qualified engineers and managers have a life expectancy at birth of 80 years and 79.4 years respectively. People in unskilled manual occupations, such as labourers, have the shortest expectation of life, living to 72.7.

However, statistician Brian Johnson, who produced the report, told B&E online that the data collected was based on a method seen as outdated by many social scientists.

He said: “The reason we used this method and not the current Social-Economic Classification, which is based on occupation, size of industry and employment status, was that it is a long-term study and we needed to have a measure that was in place in the early 1970s when this study began.”

Johnson confirmed that the format does still show up differences in health and mortality, but warned that there is an overlap between the classes.

He said: “There are top professional people who die young and there are people in very unskilled manual workers who go on to live to over 100. This is all a matter of averages.”

Johnson said that despite there being research published into why there is nearly a ten-year gap between the classes, all the usual reasons have been shown to have an effect, and particularly he warned, smoking.

He said: “People in the so-called lower manual groups continue to smoke more, even now, than people in the higher social groups. Smoking is one factor. Then there are all the usual cases, such as excess alcohol, diet, lifestyle, stress; all of those sorts of things have been shown to have an effect. I don’t think anyone could truly explain all the differences in social class in terms of these factors.”