Shocks have been sent across the mortgage market following Northern Rock's falling share price.
Many customers and investors have pulled their funds, sending the situation into a spiral into which other banks are being drawn.
Banks have begun to face problems within their usual culture of interlending as the US sub prime mortgage crisis has led many banks to restrict their lending policies.
The bank is Britain's second-largest mortgage provider, after Northern Rock, with 5.5 million mortgage customers.
The bank has denied claims that it is to seek assistance from the Bank.
In a statement the company said: "We have not approached the Bank of England for assistance. We have a very different business model to Northern Rock and our funding is not overly reliant on wholesale markets."
If more banks are to follow the path of Northern Rock, the government could face significant pressure to reimburse savers.