The Budget launched what looks like a voter-pleasing Help to Buy ISA which will act as a 25% top-up on deposits.

The Chancellor described it as a tax cut for first-time buyers. One delighted agent called it a “very juicy carrot”.

However, there are also warnings that the scheme will need to be tightly policed to prevent savers misusing the scheme and spending the money on other things.

For every £200 that an intending home buyer saves for a deposit into the new ISA, the Government will top it up by £50.

Chancellor George Osborne said the new scheme could be used by an average first-time buyer needing a 10% deposit of £15,000. They would now only need to save £12,000, with the Government topping up the amount by £3,000.

He told MPs: “A 25% top-up is equivalent to saving for a deposit from your pre-tax income – it’s effectively a tax cut for first-time buyers.”

The scheme will be available on properties worth up to £450,000 in London and up to £250,000 outside the capital. It could also be used by couples buying a home together, potentially doubling the Government’s contribution to the scheme, which is planned to launch this autumn.

It met with a largely enthusiastic reaction from the industry.

Paul Smith, CEO of Spicerhaart, described it as “a fantastic incentive to start saving”, while Paul Beresford, of Beresfords Group in Essex, called it a very juicy carrot which would “significantly help those trying to save in a climate of low interest rates”.

Mark Hayward, managing director of the NAEA, said: “This initiative will provide a significant boost to the ability of a first time buyer to save speedily and effectively.

“This is exactly what is needed to engage the first-time buyer market, particularly as we have seen the current criteria under the MMR constraining aspirations to buy a home.

“It especially benefits couples who are buying for the first time as both are eligible to open a Help to Buy ISA which potentially means £6,000 from the Government bonus towards a new home.

“It is also timely, considering house price inflation outpaces wage inflation, so this additional boost to first-time buyers’ savings pots will help them at least keep apace rather than fall behind the inflationary curve.”

Adrian Gill, director of Your Move and Reeds Rains estate agents, said it was the Chancellor’s “trump card” but warned it crept round the elephant in the room.

He said: “This significant new ISA scheme will help thousands of aspiring homeowners accumulate what they need to jump on to the property ladder.

“First-time buyers have been dealt a cruel hand in terms of affordability lately. Interest rates on savings are low, house prices have largely been on the up for the past six years, and – until recently – earnings haven’t followed suit.

“This short cut to saving for a deposit will bring home-buying within range for many more, and consumer confidence will certainly shoot through the bottom rungs of the market.”

However, Gill warned: “But the announcement tiptoes around the elephant in the room.

“It’s all well and good getting first-time buyer finances in shape, but it will amount to hollow words if there are no properties available for them to buy, and if competition continues to push house prices higher and higher.

“Helping home owners requires both sides of the conundrum to be tackled. The Chancellor has certainly done a good job of boosting demand – but now more needs to be done to sort out supply.”

Mortgage broker Ray Boulger, of John Charcol, said: “The scheme will need to be robustly policed to make sure the savings are not used for other purposes.”

He also said that the fact that savers had used the Help to Buy ISA would not guarantee them a mortgage.

The most dissenting voice came from Matt Hutchinson, director of flat and house share website Spareroom.

He said that to get a £3,000 bonus, saving at the rate of £200 per month into the ISA would take four and a half years.

By that time, he said, “prices will likely have risen again and a £15,000 deposit won’t be enough.”