Kensington and Chelsea is one of the few areas in the UK where the population dipped during the last ten years, according to union research.
The London borough was alongside Blackpool, Blaenau Gwent, Stockport and St Helens as one of the only places in the country to see such a fall.
Research by union GMB showed there was extra strain on utilities and services because everywhere else in the country, populations increased between 2001 and 2011.
The study of 174 shire counties, London and metropolitan boroughs and unitary authorities in England and Wales, revealed population growth ranging from 3.2% in the North East to 14% across London.
The analysis showed that there were 41 areas of England and Wales where the population grew by 10% or more between 2001 and 2011, including Tower Hamlets in London (29.6%), Manchester (28.1%), Newham (26.3%), Hackney (21.4%), Westminster (21.%) - all London, Milton Keynes (20.2%) and Hounslow (19.6%).
The analysis revealed that the population rose in all 10 regions in England and Wales between 2001 and 2011, led by London (14%), and followed by the East Midlands 8.7%, East of England 8.5%, South East 7.9 %, South West 7.3%, Yorkshire and The Humber 6.4% West Midlands 6.4%, Wales 5.5%, North West 4.8% and North East 3.2%.
National officer Brian Strutton said: "These figures show that many areas need more schools, more housing, improved transport links, more health facilities, upgrades in utilities like water and more recreation facilities. There is a need for a step change in how we care for growing number of the elderly and in particular how can we help them stay in their own homes for as long as possible.
"National and local government and the private sector must use this growth in population as the springboard to reflate the economy by providing the social infrastructure this population needs.
"Leadership is needed to deliver such a programme as well as the £200 billion investment to deliver essential energy and infrastructure projects. It is a bigger challenge than delivering the Olympics."
