It blamed the increase on large mortgages, rising school fees and people borrowing to keep up with the lifestyle of their neighbours. The charity found that the highest proportion of middle-class people struggling with debt were in the counties around London.

Author of the report Helen Saxon said: "Accepted wisdom suggests that a take-home income of £30,000 per year is enough to allow most families to be able to manage the demands on their income.

"But large mortgages, rising school fees, keeping up with the Joneses and the increasing availability of credit have made debt a normal part of life for many of the middle class."

Britons now collectively owe more than £1 trillion on mortgages, loans, credit cards and overdrafts.

Ms Saxon said that credit was more easily available to people with higher incomes, as lenders considered making loans to them to be less of a risk than advancing money to someone on a low income.

Since 2003, the charity has seen a 257 per cent rise in those earning more than £30,000 a year and seeking debt help. These now number 3,000 and account for one in 20 of the council's clients.

It said this may be because soaring house prices in the South had led to people taking on mortgages with high monthly repayments, which ate away at their disposable income and forced them to turn to credit to bridge the gap between their incomes and their outgoings.

The Council said the average person earning more than £30,000 had debts of £69,737 owed to nearly 13 creditors. Those those earning less than £10,000 had average debts of £20,316 owed to just seven creditors.

The Council's report comes as other research showed an estimated one million people were considering declaring themselves insolvent, as increasing numbers struggled with five-figure debts.

One in five people now owes more than £10,000 through credit cards, overdrafts and loans, according to debt consultancy Thomas Charles.

More than one in five with debts of this size admit they frequently have problems meeting their repayments, 9% of whom say it is a struggle every month. Almost a quarter blamed debt on overspending, while 21% said it was because of poor cashflow and 13% said it was a legacy of being a student.

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