Public health experts sometimes rework the map of a city’s train or underground system to illustrate the wide differences in life expectancy between wealthy areas and poor ones. For example, every one of the eight stops travelled on the London tube’s Jubilee line east from Westminster, the heart of government, to post-industrial Canning Town in the East End counts for up to a year in diminished life expectancy.

In Glasgow, in the course of the seven-stop trip south-east from Jordanhill to Bridgeton, the average male life expectancy drops from 75.8 years to 61.9 years. In Newcastle upon Tyne, adults living near the airport can hope to remain free of disease and disability – to enjoy healthy life – until just before they turn 75. But a few miles east in Byker that enviable period typically ends before the official retirement age, at just 63.8 years.

These stark differentials are perhaps the most arresting illustration of the wide, enduring inequalities in health. Many doctors and public health campaigners believe they give the lie to the idea of Britain as an equitable, civilised country. Our poorest people are those most likely to contract cancer, heart disease, diabetes, liver disease, breathing problems – pretty much every life-shortening condition there is. The result is usually premature death.

On 13 July last year, setting out her priorities as the new prime minister, Theresa May expressed her commitment to representing every strand of society. On the issue of health, she pledged to fight “against the burning injustice that, if you’re born poor, you will die on average nine years earlier than others”. In England the coalition’s controversial Health and Social Care Act 2012 places the health secretary under “an overarching duty to have regard to the need to reduce inequalities between the people of England with respect to the benefits that may be obtained by them from the health service”.

But as David Buck, the expert who has analysed how the government’s 15 key measures of health inequality have been faring since the coalition’s early years, points out, the phrase “have regard to” is vague and non-directive. It does not require the current health secretary, Jeremy Hunt, to do much to tackle the long-established gulf in life expectancy between citizens.

Hunt may contend that there is only so much a health service can do in this respect anyway. Certainly, only sustained action by the full machinery of government could banish the close correlation between someone’s socio-economic circumstances and their risk of death.

But Buck says his new research should be a wake-up call to ministers. He has found that, according to all the 15 measures used by the Department of Health to track them, health inequalities worsened under both the coalition and the early period of the Conservative government. For the past seven years, the gap between health outcomes experienced by the richest and poorest has widened, not narrowed. Compared with the better-off, England’s most deprived citizens have become more likely to live a short life, lose a child at birth, be beset by disability or chronic illness, or die from cancer, stroke or a heart attack before reaching 75.

On one level this widening of health inequalities is an unpleasant surprise. Prior to 2010 the figures were heading in the right direction. Only two years ago, Buck and a King’s Fund colleague, David Maguire, found that the gap in life expectancy between England’s richest 10% and poorest 10% of the population shrank by 2.5 years, from 6.9 to 4.4 years, between 1999 and 2010. The fastest improvements had occurred in areas with the highest levels of income deprivation. The reasons were complex but they highlighted the Department of Health’s strategy of targeting places with low life expectancy. The local NHS in such areas was given more money and patients encouraged to start treatment for conditions such as diabetes and high cholesterol.

So are the austerity policies that kicked in after the financial crash to blame? The causal relationship between specific socio-economic factors and health outcomes and early death is hard to prove. But some experts fear the worst.

Professor Danny Dorling, an expert in inequality, has highlighted NHS England (NHSE) research published in October 2014 about what officials call potential years of life lost – early mortality. It said that data the Office for National Statistics passed to NHSE “shows that PYLL [potential years of life lost] in men has been improving steadily until 2010 but in 2012, 2013 and 2014 the improvement has been much more gradual”. For reasons unknown, male PYLL had deteriorated for the first time in April 2013.

Last month Professor Sir Michael Marmot, who undertook a major review of health inequalities for Gordon Brown when he was the prime minister, identified that a century-long increase in life expectancy had plateaued since 2010. Asked why, Marmot – the doyen of British experts in health inequalities – pointed to the “miserly” funding of the NHS and social care since 2010.

“If we don’t spend appropriately on social care, if we don’t spend appropriately on healthcare, then certainly the quality of life will get worse for older people and maybe the length of life too,” he said.

Buck’s new analysis will raise similar questions, about whether the seven-year-long drive to rebalance the nation’s finances, with its squeeze on NHS and councils’ spending and welfare cuts, has come at the expense of poor people’s health and their lives.