Scots are missing out on a potential multimillion-pound refund on illegal and unfairly high banking charges because of restrictions in the legal system, it is claimed.

Consumer groups and legal experts say the poorest debt-ridden people in Scotland are hardest hit by a north-south divide on small claim awards in courts.

In England and Wales the maximum claim is £5000, but in Scotland's sheriff courts the limit is £750.

There is also concern that, under Scottish law, claims cannot be more than five years old.

Some legal experts are now advising Scots making claims to take their cases to England.

Pressure is growing for a review of Scotland's civil courts - being carried out by Lord Gill, Lord Justice Clerk and the nation's second most senior judge - to find a way of ending the disparity.

Julia Clarke, Scottish spokeswoman for the consumer association Which?, said: "We cannot get redress in Scotland the way English and Welsh consumers can. And we know there are cases where Scots are going across the border to access their legal system in claims because our legal system is so poor.

"The limit for small claims actions has been frozen for 15 years at £750.

"It is a pitiful limit and it is an absolute disgrace."

It is estimated that up to 500 bank customers a day in Scotland register a complaint with the financial ombudsman over high penalty charges. Campaigners say that charges of up to £39 levied by banks when a customer's cheque bounces or the overdraft limit is breached are illegal.

They also claim that other charges, such as mortgage administration and exit fees, are unfairly high.

Govan Law Centre (GLC), which provides free Scottish debt law advice, is to call for the maximum award for claims on unfair and illegal penalty charges across Britain to be set at £10,000.

In a report to the government Scottish Affairs Committee inquiry into poverty in Scotland, the GLC lists unfair bank charges as a cause of deprivation north of the border because many people on low incomes are being crippled by "a cycle of debt".

The GLC has already helped consumers across Britain win back nearly £1m in refunds.

Mike Dailly, GLC's principal solicitor, said the key way for the poorest to gain legal recourse was through small claims actions which cost up to £65 each. The alternative route, he said, was an expensive ordinary cause action for claims in excess of £1500 to the sheriff court.

The GLC also revealed it had been involved with repossession cases where more than one-third of mortgage arrears was made up of bank penalty charges.

A Scottish Executive spokesman said: "The executive supports an increase for these limits and has been actively engaging with stakeholders."