Some companies have claimed the rising fees required to service the product after interest rates fell in 2008 have forced them out of business.
The City watchdog is expected to confirm that banks are writing to customers who have taken an Irsa and an independent assessor will look at the most complicated cases and determine whether compensation should be paid.
The claims echo the payment protection insurance (PPI) scandal that emerged last year, costing banks billions of pounds, and come in the week Barclays was fined £290 million for manipulating interest rates.
Bob Diamond tonight angrily rejected suggestions that he misled MPs over regulators' concerns about activities at Barclays.
The Bank of England's Paul Tucker told MPs he refuted claims that he attempted to influence Barclays into manipulating the Libor rate.
MPs will be hoping the Deputy Governor of the Bank of England will shed some light on unanswered questions about rate-fixing at Barclays.