A surge in demand for rental accommodation over the summer has outstripped supply.

The quarterly review by Winkworth estate agents shows that tenant registrations soared over July and August, finishing 47 per cent up on May.

It meant in all that the number of potential renters in August was up 14 per cent on last year but the number of rental properties on the market in August was more than 50 per cent lower than a year ago.

Winkworth chief executive Dominic Agace said: "Rentals have seen price increases following a shortfall in investment in the sector by private landlords.

"This is due to the suspension of buy-to-let mortgage products over the past two years and the selling-off of 'accidental landlord' properties.

"While there has been some renewed supply of buy-to-let mortgages, these remain expensive for buyers with less than 20 per cent equity, and with the increase in capital gains tax, ongoing supply constraints will continue to support rents."

The demands for high purchase deposits mean that increasing numbers of first-time buyers are struggling to get mortgages and are renting for much longer.

The upshot of this is that the National Housing Federation recently announced that the average age of a first-time buyer has risen to 43.

As a result, properties are not coming on to the market, and limited buy-to-let mortgage options are preventing landlords from strengthening their portfolios and bringing fresh stock to the market.

This increase in demand and shortage of stock has led to a year-on-year rent price increase of five per cent, broadly in line with inflation.

Mr Agace said continued supply-and-demand pressure is likely to push average rents up further this autumn.