This might be a daft question, but I have a lot of £ in HBOS accounts and what would happen to it if HBOS went down?
Protected by the Bank of England's depositors scheme, up to a point
"UK banks are required to be members of, and to contribute to, a deposit protection scheme. This entitles depositors with a failed institution to receive 90% of their protected deposits, subject to a maximum payment to any depositor of £18,000 ."
Would it be better to plough some of your savings into the shares then?
As per NRK though, highly unlikely the bank of england would get it that far (Lehmans in the US isn't a retail bank)