National Savings is launching a Tessa Isa for investors offering investors 5.75 per cent gross.
The Tessa Isa guarantees to pay an interest rate equal to or higher than the Bank of England's base rate until April 2000.
The Tessa Isa is only available to savers with maturing Tessas.
The minimum investment is £10, with a maximum of £9,000. But this maximum is restricted to the amount previously held in the matured Tessa.