Despite buyer demand being at its highest for six years, housing transactions this year are likely to be only 75% of the long-term norm, Countrywide said this morning.

The firm said that the number of buyers chasing each new property is the highest since 2008. On average, there are 12 buyers per property, but in London the figure is more than double, with 25 buyers for every property that comes on the market.

Countrywide said the widespread shortage of stock is at its most acute in London where it has fallen 20% in the last year.

The findings emerge in the estate agency chain’s quarterly review of the housing market, which also says that the Help to Buy equity loan scheme is responsible for one in three sales of new homes in the north-east. In some parts of the region the proportion is 50%, compared to 9% in London.

In the first ten months of the Help to Buy equity loan scheme being introduced, a total of 14,823 new properties were bought through the scheme, the majority by first-time buyers. A further 4,666 new homes have been reserved.

Countrywide said that this equates to one in five (19%) of all new private homes built in England being sold through the scheme.

House builders in areas of the north-east in particular, where house prices remain well below 2007 levels, have relied heavily on the scheme to sell houses. In Newcastle, 49% of new private homes built in the past nine months have been sold using an equity loan.

Grenville Turner, Countrywide’s chief executive, said: “Claims that the Help to Buy scheme is causing a housing bubble are far from the truth and the facts speak for themselves.

“As a proportion of transactions, both parts of Help to Buy together support only 2% of transactions in London compared with 10% in the north-west, where support is most needed.

“The scheme has had a positive impact on house-builder confidence with many now believing that they can sell what they build, which as we know means they will build more.

“The extending of the equity loan guarantee allows developers to plan with some certainty that demand will continue to exist in 12 months’ time and goes some way to bridging the increasing gap between new supply and demand for property in the UK.”