The gap between the lifespans of rich and poor people in England and Wales is rising for the first time since the 1870s.
Everyone may be living longer but rich people's lives are extending faster, the City University London study says. Better life expectancy narrowed the gap in the early 20th Century but this trend reversed for men in the 1990s.
Researchers measured the differences in age between the youngest 10% of adult deaths and the oldest 5%. From 1870 to 1939 the gap steadily closed, the report said.
"Everyone benefited from improvements in clean drinking water, better housing, higher incomes and better health," said Prof Mayhew.
After 1950 there were further rises in life expectancy - though inequalities in lifespan persisted rather than narrowing further. But in the 1990s lifespan inequalities actually worsened, particularly for men, for the first time since the late 1870s, say the researchers.
They found that for men who died in 2010 aged over 30:
the oldest 5% reached an average age of almost 96 but the youngest 10% died at an average age of just over 62 - more than 33 years younger
By 2009 this longevity gap was 1.7 years greater than it had been at its narrowest in 1993
For women who died aged over 30 in 2010:
the oldest 5% reached an average age of just over 98, the youngest 10% died at an average age of just over 67 - a longevity gap of 31 years
For women this gap was narrowest in 2005