I have had a current account mortgage - The One Account from RBS (originally Virgin) - since 2003. The idea of these accounts is that your current account and mortgage debt are combined into one account, and all your salary and other deposits into the account immediately reduce the amount owed, thereby saving you interest at a higher rate than you could earn in a savings account. It's similar to an offset mortgage, but without splitting the savings part off into a separate account.

My loan facility ("credit limit" if you will) is £200,000 but currently my debt balance is floating around £160,000, so in effect I have an available "emergency fund" of about £40,000.

I've recently become aware that in the US, people with accounts like this (known as "HELOC", Home Equity Line Of Credit accounts, over there) were getting into trouble because the lender would lock the account against withdrawals, without warning. This was a response to falling house values which obviously increased the lender's risk. This can be a big problem, as you suddenly lose access to your "emergency fund".

Has anyone heard of anything similar happening over here? Should I be worried enough to consider remortgaging?