Chancellor George Osborne unveiled a Help to Buy ISA in his Budget, aimed at helping first-time buyers get into the housing market.

The offer will become available in autumn 2015 for a period of four years, and is only available for first-time buyers. They will be able to open an ISA up with a deposit of £1,000, so this delay at least gives them some time to begin saving. However, only houses outside of London worth up to £250,000 will be eligible, whilst in the capital, the limit is £450,000.

Making use of this ISA is a way for buyers to ‘top-up’ their savings, with the government contributing 25p for every £1 you save. But, they are limited to saving £200 a month, meaning it will take you four and half years to save up to the limit of £12,000. Doing so will result in you qualifying for the maximum state ‘top-up’. If you have £12,000 saved, the government will end up giving you £3,000, leaving you with a total of £15,000 saved for a deposit.

This would mean that if you were saving for a 10 per cent deposit on a house worth £150,000, you would need to save £12,000 rather than £15,000.

There is also no limit on the number of Help to Buy ISAs used when buying a house, so if you are buying with two other people for example, you can use three ISAs to help fund the deposit on the house.

However, critics believe that it will actually result in first-time buyers finding it even harder to get onto the property ladder than before, saying that house prices will actually increase as a result.

The Institute for Fiscal Studies (IFS) highlighted that there are not enough new homes available, so failing to build more would lead to an increased housing demand.

“Ultimately, what will make housing affordable is building more houses,” said Stuart Adam, of the IFS.

They also felt that the people who would benefit the most would be those first-time buyers who already have a generous amount saved for a deposit.

“Certainly those who find it easiest to qualify for the maximum top-up are going to be those who have the £12,000 of savings anyway,” added Mr Adam, “or have wealthy parents and will be able to drip it in to the ISA.”