Hansen Lu, an economist at Capital Economics, said: "This data is somewhat surprising. We expected that the introduction of the stamp duty surcharge would have led to both cooling price growth and transactions.

"But in theory, the sharpest drop should have occurred in April, immediately after the introduction of the new tax. Yet the slowdown appears to have intensified in May.

"One explanation for this could be that April’s data was propped up by new owner occupier buyers who opportunistically chose to enter the market during what they knew would have been a period of quieter demand.

"Another possible explanation is that some would-be buyers are now being deterred by a combination of economic and EU referendum uncertainty. And some, conscious that house prices are already high, might also have been put off by signs that the housing market is starting to cool."

The Rics residential market survey is widely seen as a good indicator of future house price changes.

Mr Cook said: “The Rics survey is likely to be one of the few measures that picks up the impact of the pre-referendum uncertainty before the vote actually takes place. Historically it has proved a very good lead indicator of the direction of travel in the housing market both at a national and regional level.”

Samuel Tombs, chief economist at Pantheon Macroeconomics, said: "House price growth is weakening, but this slowdown appears to entirely reflect Brexit risk, not fundamental factors." He said that the main area of caution is London, where foreign buyers have been cautious over a potential vote to Leave.

He added: "Provided the UK votes to remain in the EU this month, house price growth likely will accelerate again in response to falling mortgage rates and rising wage growth."

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