A surge in winter deaths among the elderly last year was today blamed in part on flu and a less-than-effective vaccine for the virus.
Excess winter deaths jumped last year by 151%, official figures show, with the majority of deaths among those aged 75 or over.
The figures, released by the Office for National Statistics, estimated that there 43,900 excess winter deaths in England and Wales between December 2014 and March 2014.
That figure is the highest since 1999/00 and the first time excess deaths have exceeded 40,000 this century.
Claudia Wells, the head of mortality statistics at the ONS, said: "While the cold temperature is a factor, most of last winter was warmer than average. A major cause behind the rise was the flu virus, with estimates showing that the flu vaccine was not as effective this winter compared to previous years."
Respiratory diseases were the underlying cause of death in more than a third of all excess winter deaths in 2014/15, with pneumonia accounting for the largest proportion of these deaths.
The figures buck a trend of decreasing winter mortality over recent decades, but the record low number of deaths in 2013/14 - 17,460 - corresponded with an exceptionally mild winter where the average temperature was 6.2C. Last winter the average temperature was 4.8C.
Excess winter mortality is the difference between the number of deaths in the four winter months, December to March, compared to the average number of deaths over the rest of the year.
Last winter also saw a record high in deaths caused by dementia and Alzheimer's disease, with 9,100 excess winter deaths recorded.
The excess winter mortality index was highest in the South West in 2014/15 and joint lowest in Yorkshire and The Humber, and Wales.
The National Pensioners Convention (NPC) called on the government to launch a new fuel poverty commission in response to the surge.
Dot Gibson, the NPC general secretary said: "Successive governments have simply ignored the problem of winter deaths amongst the older population and seem to have a policy of crossing their fingers and hoping things will improve. Today's figures show that this policy simply doesn't work."
NPC members will release one black balloon for every 1,000 people who died last winter from cold-related illnesses at six places across the country, including Westminster.
Age UK called on the Government to make energy efficiency a national infrastructure priority. Caroline Abrahams, one of the charity's directors, said: "Many countries with colder climates than ours have far better records on cold-related deaths, showing we should be doing much better than we currently are. Cold homes have life and death consequences for older people and we should be deeply ashamed of that in an affluent country like ours".
Janet Morrison, the chief executive of Independent Age, the older people's charity, urged the Government to fight fuel poverty and individuals to look after elderly relatives.
She said: "This isn't just a story about cold weather; it's a story of cold, damp and poorly insulated homes and pensioners who can't afford to pay heating bills."
"Tragically, the influenza vaccine was only effective in a third of cases last winter, which appears to have been a major factor in the rise. But even discounting the impact of the flu, the figures are still far higher than in previous years."
Heidi Alexander, Labour's shadow health secretary, called the figures "a national scandal".
She said: "Many of these excess deaths are caused by people living in homes that are too cold, and alongside action on social care, the Government needs to gets serious about tackling fuel poverty. Home insulation has fallen by 80% under the Tories and is set to be cut back even further.
"Older people should not have to choose between heating and eating."
A Department of Energy and Climate Change (Decc) spokesman said: "Keeping bills down for hardworking families is a priority and we are taking action to support those who need it the most.
"Improving the energy efficiency of people's homes is one of the ways we can help to tackle fuel poverty. As part of this we're supporting schemes like the Warm Home Discount, Winter Fuel Payment and Cold Winter Payment, delivering vital financial support to vulnerable households."
The Decc pointed to its raising of the Cold Weather Payment from £8.50 to £25 for each spell of very cold weather, saying that it issued the payment, for which pensioners are eligible, 422,000 times last winter.