Britain's banking market has shifted into a two tier system, government banks and private banks, according to NAB CEO designate Cameron Clyne.And while NAB is yet to make any drastic additional provisions the bank is realistic about the outlook for its subsidiaries NAB Europe and Clydesdale Bank.Clyne said that if it were not for Northern Rock in effect forcing customers to refinance, and thus run down the lending book now owned by the government, there would be no mortgage market activity in Britain at all.Other government-owned banks in Britain are RBS and Lloyds/HBOS following capital injections earlier this month.NAB is also eligible to seek government funding for Clydesdale Bank (both equity and guaranteed term debt) but management is reserving its position for now.NAB's view is that with Clydesdale essentially funded off deposits rather than wholesale liabilities, and with a business franchise centred on northern England and Scotland (described by the bank as "deposit rich"), the bank can respond to evolving opportunities.The bank said a 20 per cent decline in property prices in Britain would double current levels of provisions.