The Government is being urged to launch an inquiry into why life expectancy rates in Britain have stalled.
Sir Michael Marmot, the author of a government-ordered report on health inequality, said the country risked becoming the "sick man and woman of Europe".
He compared progress in Britain to that of other European nations, many of which have longer life expectancies.
His analysis found that according to the EU statistics body Eurostat, the gap is getting wider, with growth in female life expectancy at birth the worst in Europe and male growth the second worst.
Sir Michael, director of the Institute of Health Equity at University College London, wrote in the Times: "Were this to keep up, we would soon become the sick man and woman of Europe. This is a new and worrying trend."
In Britain, the female life expectancy at birth is 83, below the EU average, while for men it is slightly above the average at 79.
Sir Michael has written to Health Secretary Jeremy Hunt urging him to set up an inquiry into the slowdown, saying that "austerity is an obvious candidate".
He found that while life expectancies had slowed across all countries since the global financial crisis, it has been "particularly marked and pronounced in the UK", which slipped from the middle of the table to the bottom of the pile.
A Department of Health spokeswoman said: "Health inequality is a challenging and complex area - deeply rooted, difficult to turn around and driven by a variety of factors.?
"Despite widespread variation, smoking rates are at an all-time low and cancer survival rates at a record high.
"We are investing more than £16 billion in local government services over the current spending period to help tackle public health issues, in addition to free NHS health checks, screening programmes and funding for campaigns such as Be Clear on Cancer."