Last year's stamp duty increase has reduced annual prime central London sales volumes by 15%, according to Knight Frank.


In the 2012 Budget, chancellor George Osborne announced that stamp duty on homes sold at a price over £2m would increase from 5% to 7% with immediate effect.


Knight Frank's global head of residential research Liam Bailey said that during the six months following last year's Budget the impact of the move was dramatic as the volume of £2m-plus sales fell by between 25% and 35% across London.


But Bailey said that the market has since reacted more positively following the publication of the draft 2013 Finance Bill in December, which provided some clarity around the wider £2m-plus residential property tax environment.


He estimated that transactions in the £2m-plus residential property sector will be around 15% lower in the 12 months to the end of March 2013, compared with the same period a year earlier.


Based on published HMRC data this would point to a total of 3,400 transactions as opposed to 4,000.


But prices in the sector have increased by 8.4% over the past 12 months, meaning HMRC will have collected some £223m in additional tax revenue since the 40% rise in stamp duty was implemented in 2012, £73m more than originally forecast.


At the lower end of the prime market, meanwhile, sales of £1m-£2m homes are likely to have increased by around 5% over the same period.


Bailey said: "While the announcement in the Autumn Statement that the chancellor planned to introduce "no new property taxes", combined with the clarity provided by the draft Finance Bill, which encouraged potential purchasers to return to the market at the latter end of the year, we believe the longer-term impact of the stamp duty increase has been to reduce total £2m-plus sales by around 10% below the level they would otherwise be if the new stamp duty rates had not been introduced."