Northern Rock has plunged £584 million into the red since it was nationalised. The Government-owned bank said its huge losses were largely down to a dramatic increase in its mortgage and loan customers being unable to keep up their payments. Loans that aren't insured by the government are called conventional mortgages. The government-insured loans may be more attractive in terms of low down payment requirements but they may be more restrictive. The main advantage of applying for online mortgages is their convenience.