The proportion of first-time buyers paying stamp duty has leapt from 48% to 56% in the space of just a year, according to the Council of Mortgage Lenders (CML), while only 5% of home movers escaped the tax in August, compared with 21% a year earlier.

CML director general, Michael Coogan, said: "Overall affordability has worsened a little, especially for first-time buyers. Over the period of a year, small monthly changes can nevertheless be significant - as the rise in the proportion of mortgage borrowers required to pay stamp duty shows. For the rest of this year, we expect some moderation in activity although the market is continuing to outperform our earlier forecasts."