They aren't really borrowing money. They're having to post collateral against derivatives (probably interest-rate swaps) that have moved against them. Those sw

They aren't really borrowing money. They're having to post collateral against derivatives (probably interest-rate swaps) that have moved against them. Those swaps are supposed to be a hedge against falling interest rates: they lose money in a rising rate environment, and the colossal bungling of the UK economy by the current government has resulted in such large and rapid rises in gilt rates that the collateral calls exceeded cash available to meet them.