Legal firms and claims management organisations are currently assessing mortgage mis-selling claims as the payment protection insurance scandal finally draws to an end.

Mortgage mis-selling could rank alongside PPI, according to experts, with potentially billions due to customers who were wrongly advised to take out interest-only products, leaving them without a way to repay the loan when it becomes due.

There are about 2.6 million interest-only residential mortgages that will mature between now and 2041, according to the Financial Conduct Authority’s (FCA) review of the market in 2013. Of those, 600,000 will mature by 2020, The Times reports.

Each month thousands of people have no other option but to move out of their homes in order to pay off their mortgages or face financial ruin if their home has decreased in value and the sale proceeds to not cover the costs of the loan, lawyers have said.

Rob Cooper, chief executive of ME Group, which specialises in legal claims, said: “In the aftermath of the financial crisis, the banks were bailed out at the taxpayer’s expense, US investors in mortgage-backed securities were compensated. The only group of people still paying the price of the financial services industry’s poor conduct are consumers who hold unsuitable, unaffordable and overcharged mortgages.

Lawyers who have begun to bring claims argue that mortgage brokers pushed customers into interest-only loans because they often came with higher commissions paid by lenders. But many of the customers could, in fact, have afforded repayment loans, according to the lawyers.

Monthly payments for interest-only products are lower than for repayment loans, which also reduce the capital. However, many interest-only customers have not saved money to repay the loan.

The FCA has estimated that 48% will have an average shortfall of £71,000 on their loan.

The regulator’s research indicated that 90% of interest-only borrowers had some repayment strategy, but 21% of those said their plan was to sell their home.

Those most affected tend to be financially vulnerable people, who had fewer choices or less ability to make other plans to pay off the capital.

Unlike PPI, which has cost banks £50 billion, mortgage mis-selling could land at the doors of brokers as they were made responsible for advice to customers by the financial regulator in 2004.