This figure is 78% higher than in May 2019, while at the start of the year the sales pipeline across Great Britain stood at 613,000.
Research among buyers expecting to benefit from the stamp duty holiday has found only 4% would abandon their plans to buy a property if they missed either the June or September deadline in England.
Of those hoping to complete prior to the September deadline, only 29% of buyers expect to be able to do so; more than half (53%) said they would go ahead as planned, one in four (25%) said they would try to renegotiate with the seller, and 13% said they would plan to buy a cheaper home.
Of the 704,000 sales going through the Rightmove pipeline, 220,000 were marked as sold subject to contract between July last year and the end of February this year in England and are yet to complete.
Of this 220,000, there are 131,000 that are over £250,000, making this group in most urgent need to get their sale over the line before the end of June.
The current average time from sale agreed to completion is four months.
Tim Bannister, director of property data at Rightmove, said: “The easing of restrictions, extended stamp duty holiday, better mortgage availability for first-time buyers, race for space and relocation plans have all combined to create the biggest conveyancing logjam we’ve ever recorded over the past 10 years.
“We really hope those who had at least four months to make it through to completion will make it in time to beat the first stamp duty deadline, but with the tapering until September many will still make some savings so all will not be lost.
“The pace of properties coming on and off the market is also the quickest we’ve recorded, and agents are telling me they have multiple viewings followed by a number of offers within days of a property first appearing on Rightmove.
