New figures from the Office of National Statistics' (ONS) 2014-16 wealth in Great Britain survey has revealed growing UK household wealth is overwhelmingly weighted towards older and wealthier Britons.
The data showed that the number of millionaire households in Britain increased to 3.6 million between July 2014 and June 2016, representing a 29% increase. Total UK household wealth was £12.8tn - a record high.
Private pensions and property holdings drove much of the increase, further widening the gap between the UK's haves and have-nots.
There was a 20% increase in private pension wealth to a total of £5.3tn. Property wealth went up 17% to £4.6tn over the same period.
The wealth held by the top 10% of households was around five times greater than the wealth of the bottom half of all households combined, the ONS reported.
The poorest fifth of UK households actually saw their wealth fall in real terms.
The median average wealth per British household was £259,400, after taking borrowing into account. This is 15% higher than two years previously.
London was the wealthiest area of the country, where the median household wealth was 62% higher than in 2006-08. The main driver of this was property values, which have doubled over the past decade in the capital. In the East Midlands and North East, median household wealth was 14% lower than 2006-08.
Conor D'Arcy, senior policy analyst at the Resolution Foundation, which lobbies for low-income groups, said: "Britain is very good at generating wealth, but terrible at spreading it around the country and even worse at taxing it properly. As a result, we have unacceptably high levels of wealth inequality.
"Young people in particular are feeling the effects of Britain's wealth divide. Our large millennial generation own just two percent of the nation's wealth. This stems from their struggle to get on the housing ladder, boosting other's people wealth in the private rented sector, rather than build assets of their own."
According to the statement from the Resolution Foundation, wealth inequality is almost twice that of income inequality.
"Given the huge fiscal pressures Britain will face in the coming years and decades, it is vital we do a better job of distributing and taxing wealth. Otherwise we will simply put more and more pressure on working households," D'Arcy warned.