Britons’ personal debt mountain is growing at the rate of £1m every four minutes and now totals £1.278bn, according to a survey commissioned by the Bank of England and undertaken by charity Credit Action.

Far from painting a rosy picture of UK saving and investment, the study shows that massive mortgages are primarily to blame for the problem, with the average homeloan now weighing in at £142,000.

Mortgages account for about £1 trillion of the debt mountain and Credit Action’s Keith Tondeur said: “Property looks like a very attractive UK investment, but not if that investment is more than you can realistically afford.”

Credit Action has calculated that, excluding mortgages, every adult in Britain has average debts of £4,511, including borrowing on credit cards, car finance deals and personal loans. Figures compiled at the end of last November show that the average household debt is £8,765 (excluding mortgages) and £52,811 (including mortgages).

The average owed by every UK adult is £27,180 (including mortgages), which shows the extent of the UK investment in property.

In a separate announcement the Office of Fair Trading (OFT) said that it was getting tough with 17 debt management firms which it suspects may be misleading their customers.

These firms advertise Individual Voluntary Arrangements (IVAs), where people make individual deals with their creditors which, if they agree, means a part of the debt can be repaid, normally over five years.

However, the 17 companies have been charging set-up fees to their customers and then adding on a monthly administrative charge, meaning clients often have to pay over the odds for their IVAs.