A new market-leading investment bond with a rate of 2.2% has been launched by NS&I.
But the investment bond, unveiled by the Government in the Autumn Statement, is only available to buy online - and its rate is below the Consumer Price Index (CPI) rate of inflation at 2.3%.
Savers can put between £100 and £3,000 into the deal and the 2.2% rate is fixed for three years. The bond will be on sale at nsandi.com for the next 12 months.
Announcing the launch, the Treasury said the online-only availability of the bond reflects the changing nature of customer behaviour as more money is deposited online with NS&I than via any other individual sales channels.
Economic Secretary to the Treasury Simon Kirby said: "From raising the Isa threshold to introducing the new Lifetime Isa, this government is committed to creating a nation of savers.
"With its market-leading rate of 2.2%, the investment bond will provide a valuable boost for savers who have been affected by low interest rates."
The new Investment Guaranteed Growth Bonds are for customers aged 16 or over.
Savers wanting to withdraw their money before the end of the three-year term face a penalty equal to 90 days' interest on the amount cashed in.
Someone cashing their money in within 90 days of buying the bond will get back less than they invested.
NS&I, which also offers premium bonds, is backed by the Treasury, so money invested with it is 100% secure.
The provider, which previously offered popular pensioner bonds, has more than 25 million customers.
Savers have suffered paltry rates in recent years, with further cuts made following the Bank of England base rate falling to 0.25% in 2016.
Rachel Springall, a finance expert at Moneyfacts.co.uk, said savers would need to lock their cash away for five years to get a similar rate to the new bond elsewhere.
She said Secure Trust Bank is offering a three-year deal at 2%.
Ms Springall said: "It wouldn't be too surprising to see savers flock to such an attractive offering from NS&I, however the investment would be limited to £3,000 per bond and not everyone will want to lock their cash away over the longer term."
She continued: "Luckily, the bond is expected to be on sale for a year which will mean less of a panic to grab one.
"The NS&I bond does have some flexibility unlike most fixed-rate bonds, because savers could access their cash subject to a 90 day interest penalty."
Danny Cox, a chartered financial planner at Hargreaves Lansdown, said: "As market beating as the 2.2% rate is, it still falls short of price inflation and this gap is likely to widen over the next few months.
"Undoubtedly it will be popular not least because of the Treasury backing and, unlike the pensioner bond of 2015, this savings bond is available to everyone aged 16 and over, and for a full year."
Andrew Hagger, founder of website MoneyComms, described the new bond as "little more than a token gesture".
He said: "The bond will no doubt prove popular as savers are desperate to grasp any opportunity in the current low rate climate."