An exaggerated statement that is pretty much backed up by this report from Credit Suisse in 2014:
https://publications.credit-suisse.com/tasks/render/file/?fileID=60931FDE-A2D2-F568-B041B58C5EA591A4
an extract:
"
Because income and wealth inequalities rose so much, fewer families were able to qualify to borrow huge sums of money to buy a home. Despite fewer mortgagees, but because of ever larger mortgages, coupled with the rising credit card and other borrowings of the rest of the population,
household debts have risen to record levels.
The UK did not just see debt grow, it also had the second largest growth worldwide in million-dollar-wealth households between 2013 and 2014. Almost 500,000 people tipped over that wealth bracket in those 12 months, mostly from sitting in property that was rising in value in London. This was a 30.5% increase in millionaires in a year, compared with a 14.5% rise in France, 14.1% in Germany and 13% in the US.
The UK is out of step."