National's finance spokesperson Bill English says there is still time to change the Government's deposit guarantee scheme if banks find it hard to borrow overseas.
The scheme announced on Sunday underwrites all deposits for two years for banks, credit unions and finance companies which opt into the scheme.
However it does not guarantee inter-bank borrowings, leading to fears banks will be starved of overseas funds. Borrowings are included in a similar scheme in Australia.
Mr English told Morning Report on Tuesday that there is still time to see whether New Zealand banks are being held back by the lack of a lending guarantee.
Mr English said the guarantee scheme will be tested by the tightest credit conditions seen for a decade.