THE percentage of households that fall below society's minimum standard of living has increased sharply over the last 30 years, despite the size of the economy doubling, experts say.
Researchers who carried out the largest study of poverty and deprivation conducted in the UK found the figure had increased from 14 per cent to 33 per cent.
The study involving 14,559 people said almost 18 million people cannot afford adequate housing conditions, while 12 million are too poor to engage in common social activities.
One in three people cannot afford to heat their homes properly in winter, with four million children and adults not properly fed by today's standards.
Experts, who are calling on the Government to take action, say their research shows full-time work is not always sufficient to escape poverty.
Nick Bailey, from Glasgow University, said: "The UK Government continues to ignore the working poor; they do not have adequate policies to address this growing problem."
The research was conducted by the University of Bristol, Heriot-Watt University, the Open University, Queen's University Belfast, University of Glasgow, University of Oxford, University of Birmingham, University of York, the National Centre for Social Research and Northern Ireland Statistics and Research Agency.
It found around 5.5 million adults go without essential clothing, while 2.5 million children live in damp homes. Around 1.5 million children live in households that cannot afford to heat their home.
One in four adults has an income below what they consider is needed to avoid poverty, while one in every six adults in paid work is poor.
More than one in five had been forced to borrow in the last year to pay for day-to-day needs. The study, funded by the Economic and Social Research Council, showed more than one in five adults and children were poor at the end of 2012.
The study found more people see public services, such as libraries, sports centres, museums and galleries, as "essential" than in 1999.
However, since 1999 the use of many services has declined, primarily due to reduced availability, cost or inadequacy.
Professor Glen Bramley, from Heriot-Watt University in Edinburgh, said: "It is worrying that in the 21st century more than 40 per cent of households who want to use meals on wheels, evening classes, museums, youth clubs, Citizens Advice or special transport cannot do so due to unavailability, unaffordability or inadequacy."
A Department for Work and Pensions spokesman described the report as "misleading" as "incomes have improved over the last 30 years",