Annual house price growth hit 5.1% in June despite jitters over the EU poll, according to the Nationwide House Price Index.

Average prices hit £204,968 in June, up 0.2% on May, but Nationwide is warning it will be hard to know if the expected falling demand in the coming months is due to transactions taking place earlier to beat the stamp duty deadline or because of market fears over Brexit negotiations.

A north south divide remains when it comes to house prices with the outer metropolitan area, or the London commuter belt, registering £354,787 in the second quarter of 2016, with the capital just behind at 9.9% to an all-time high of £472,384. Annual growth in London is still down from 11.5% in the first quarter, though.

In contrast, the north of England was the only region to see a house price decline down 1.1% to £123,914.

Robert Gardner, Nationwide’s chief economist, said: “It has become difficult to gauge the underlying pace of demand in recent months, due to the surge in house purchase activity in March ahead of the introduction of Stamp Duty on second homes on 1 April.

“It will therefore be difficult to assess how much of the likely fall-back in transactions in the quarters ahead is because buyers brought forward purchases to avoid additional Stamp Duty liabilities, and how much is due to increased economic uncertainty following the referendum result. Gauging the likely impact on house prices will be even more difficult.”

He said conditions in the housing market will ultimately be determined by the wider economy, especially the labour market, adding: “It is too early to assess the impact of the referendum vote on the economy. However, it is encouraging that the labour market had remained robust in recent months, with solid employment growth and the unemployment rate declining to an 11-year low in April. Borrowing costs also remained close to historic lows.

“Moreover, the lack of homes on the market – with estate agents continuing to report a record low number of properties on their books – will also provide underlying support for prices even if demand softens.”

Jonathan Hopper, of buying agents Garrington Property Finders, said this data merely shows the calm before the storm as it doesn’t reflect the leave vote at the EU referendum.

He said: “Unfortunately this data is about as much use in predicting the future course of the property market as sun-dappled photos of the summer of 1914.

“It’s a historical record of a lost age before Europe changed forever.

“The referendum result has since plunged the property market into a ‘hard reset’, especially in the higher price brackets.

“While we can’t be sure how much things will slow, it’s inevitable that more nervous investors will sit on their hands while the opportunists circle.”

He suggested prime central London would be most exposed to a lack of confidence, while outside of London it could be less dramatic.

Hopper added: “The uncertainty will do little to unblock the supply shortage. Would-be sellers will be more likely to stay put, and this tightening of supply may prop up prices to a degree.

“All this points to a soft landing rather than a crash, but the uncertainty is such that normal rules have been suspended.

“What is clear that the brisk 5.1% rate of average annual price growth the Nationwide recorded in June is likely to be the high water mark for the property market for some time to come.”