The mortgage allows borrowers to take an initial 6.45 fixed rate on 50 per cent of their mortgage and a 1 per cent discount on the other half of the loan, which gives borrowers an overall rate of 5.7 per cent.
The initial rate applies until 30 April 2004.
Charles Haresnape, head of NatWest Mortgage Services, said: "First-time buyers need all the help they can get when buying a property. This new 100 per cent deal is a winning combination that provides all-important security while not hitting them in the pocket."
There is no reservation charge and only a £1 valuation fee on the combined
Mortgage. However, the lender stipulates that the fixed and discount rates must be taken together and the loan equally divided between the two rates.