The gap in healthy life expectancy between parts of Britain has widened over the past decade to become as large as that between the UK and Sudan, a leading group of parliamentarians has warned.

In a sign of growing inequality in Britain, residents in Blaenau Gwent in south Wales can now expect up to 16.4 fewer years of good health than those in Wokingham in Berkshire, according to a report from the All-Party Parliamentary Group (APPG) on Inclusive Growth.

Led by the Labour MP Liam Byrne, the influential group of MPs and peers warned that Britain had developed into one of the most regionally imbalanced economies in the western world and required urgent reform.

“There is a growing need to shift away from trickledown economics towards a new model of inclusive growth,” Byrne said. “If current trends persist, we’ll continue making the same mistakes; prioritising the quantity of economic growth and forgetting deepening economic divisions that are splitting our society apart.”

According to the report, compiled by the Centre for Progressive Policy thinktank, levels of health inequality have risen due to factors beyond the quality of local health provision. These include crime, employment and income, as well as access to affordable housing and good quality education.

The study found that residents of the former mining towns in Blaenau Gwent spend an average 54.3 years in good health, the lowest figure in Britain and almost a decade less than a national average of 63.6 years. In contrast, the highest healthy life expectancy in Britain is in the market town of Wokingham, at 70.7 years, according to the Office for National Statistics.

The difference of 16 years is as big as the gap between the UK’s overall healthy life expectancy and the figure for Sudan, according to separate calculations by the World Health Organization.

Calling on the government to prioritise spending on wellbeing rather than economic growth alone, the report ranked local authorities using an “inclusive growth” index. Based on the healthy life expectancy, unemployment and inequality levels, as well as consumer spending and the amount of free time from work, Wokingham was also top and Blaenau Gwent bottom, closely followed by Nottingham and Blackpool.

Examining the levels of consumer spending, it said the difference between the local authority with the highest levels of household consumption and the lowest was the same as the gap between the UK and Russia.

Despite finding large differences in traditional measures of economic performance, such as an area’s contribution to gross domestic product, it warned that healthy life expectancy was the biggest driver of regional imbalances across Britain. In terms of prosperity, eight of the top 10 local authorities were in the south-east and London, while three of the bottom 10 were in Wales, two were in the north-west and two in the east Midlands.

The report also warned that many large cities had high levels of inequality within their boundaries. The study referenced a 2011 report that found gaps in healthy life expectancy could be as wide as 15.1 years within local authorities, as well as a Local Government Association report that said each stop east of Westminster on the Tube represented nearly one year of life expectancy lost.

Within greater Manchester, it found the borough of Trafford had the highest ranking for inclusive growth, with an index score more than twice that of the city of Manchester, which includes lower-income urban areas such as Moss Side. The focus on measuring inclusive growth comes amid calls for governments to look beyond traditional measures of prosperity, such as GDP, to set their spending plans based on personal wellbeing.

New Zealand earlier this year unveiled a “wellbeing budget” with large increases in funds for mental health services, child poverty and tackling family violence, calling the step a world first.

The former head of the civil service, Gus O’Donnell, has urged the government to make personal wellbeing the primary aim of government spending rather than growth in the economy.

Jeremy Lefroy, the APPG vice-chair, said: “Driving inclusive growth must be the key priority for leaders at the national and local level, going beyond GDP to redefine economic priorities for communities across the country.”