The average asking price of homes coming on to the market in Britain has hit a record high, according to new figures from Rightmove, and for the first time estate agents are listing more homes as “sold” than they are “for sale”.

The website’s monthly snapshot of new listings showed sellers are asking for an average price of £323,530, an increase of 1.1% since last month, and 5.5%, or £16,818 more than this time last year.

It is the latest in a string of reports showing a booming housing market fuelled by the temporary stamp duty holiday and a so-called “race for space” as households have been reconsidering their lifestyles during the pandemic.

Rightmove said homes were changing hands quicker than ever, leaving agents with more properties marked as sold than available for sale. However, it said there were signs that activity levels may be easing off. In September, the number of sales agreed was up by 70% year on year, but the figure has fallen to 58% so far in October.

The website said its forecast of a 2% rise in asking prices made in December 2019 looked “too timid” and it was revising up its estimates for 2020 to 7%.