The fact that Northern Rock is making repayments back to the Bank of England for the bail out loan it received seems, on the face of it, to be good news, though it could prove to be detrimental to the mortgage market as a whole.
It has been suggested that Northern Rock is only able to have overpaid on what it owes to date because it has effectively withdrawn from the mortgage market and has received significant sums of money by calling in the home loans. In the very short term it allows Northern Rock to get ahead on their payments, but in the future this means there is less money available in the mortgage market.
If there is less money available to borrow for mortgage customers then the cost of borrowing can rise further, fuelled by demand outstripping supply. Northern Rock mortgages may well come back into the market in the future but at the moment these are worrying times.