The Brexit issue may be a convenient excuse for volatile prices this year, however long before Brexit warmed up, central London was softening.
There are now fewer than half the number of buying agents than 2 years ago.
Adding 20% to asking prices above the highest recent sale has stopped. The replacement one-trick pony lowers insignificantly (£50-100k) from the latest non-viewed one.
Central prime homes are reducing asking prices by 10-15% after a few weeks' inactivity.
This is in a largely discretionary market, where selling is effectively unnecessary.
While there is still no where for money to go, there is also less money than a few years ago.
Most of us have been asking how much longer before the low interest rate world breaks. Some banks are now keeping cash in their vaults to avoid being charged negative rates by their central bank.
Of course homes under 950k or so are cheaper than they were, so those parties are still selling tickets. Homes over 5m are taking serious cuts, which they can well afford to. The people who take the fall for someone who has cashed in on 20+ years (who really could easily take the cut), nobody forced them to buy, so they are perhaps as greedy as the seller. If you are barely affording a 1m+ home, and have not walked away, then your risk appetite must be large enough to swallow the loss. There are actually a lot of high end rentals about, too... for those with smaller risk appetites.
If you can sustain the costs of a home for the time you intend to live there, even with say (shock, horror) 5% interest rates or 30% fall in price, there's no problem. They're just numbers, and will not change your day. Worry is pointless. There's a lot more stress to come, and perhaps not too long to wait either.