The number of top-end homes for sale has increased in the last week, according to Rightmove.
The property website included four-bedroom detached houses in its analysis, along with all five-bedroom or larger homes.
These are now 15% ahead of the same period last year.
Rightmove attributed the spike to a number of factors, including the mooted rise in capital gains tax (CGT) in the Autumn Budget on 30 October.
In addition to landlords, second homeowners of larger homes could be hit heavily by any increase in the tax.
Rightmove said the speculation about the tax rises is enough to prompt some of these second homeowners to “cash out” now.
It also pointed to falling mortgage rates, which are particularly beneficial to borrowers with a large deposit.
Rightmove said these borrowers would typically be more active in the large homes sector.
More sellers have been coming to the market since the cut in interest rates by the Bank of England.
However, this trend was being driven by the smaller homes sector of two bedrooms or fewer.
Regional variations
The trend of larger homes coming to the market for sale this week is most prominent in the East of England, up 21%, and the South West, up 20%.
Both of these regions contain popular coastal and countryside hotspots.
More choice of homes for sale also tends to encourage other homeowners to come to market, Rightmove said.
It means that for those looking to move within the largest homes sector, there is a much greater availability of homes to move to compared with last year.
Tim Bannister, Rightmove’s property expert, said: “Throughout this year, we have typically been seeing more activity at the top end compared with last year, as movers in this sector were hit with peak mortgage rates and lower availability of homes to choose from.
“Since the bank rate cut, the trend we were seeing is more smaller and mass-market homes coming to market for sale, but in just the last week we’ve seen a flurry of activity at the top end again.
“Some of the lowest mortgage rates since before the mini Budget are now available for those with a large deposit, and a mooted increase in capital gains tax is also likely to be contributing to decision-making right now.”
