The average price of property coming to market has increased by just 0.1%, or £248, to £309,191, between June and July, down from a 0.4% rise the previous month, data shows.

Finding a buyer this summer has been made more difficult by an 8.6% increase in new seller numbers this month, compared with the same period last year, according to property website Rightmove.

Sales agreed by estate agents are flat at 0.2% lower against the same month in 2017, so in areas of over-supply sellers have to work harder to attract a buyer.

The growth in new seller numbers and flat sales has resulted in an increase in total stock per estate agency branch. Nationally the average is 52 properties per branch, the highest level since September 2015.

Miles Shipside, Rightmove director and housing market analyst, said: “At this time of year many potential sellers are more focused on erecting sun umbrellas as opposed to ‘For Sale’ signs, and would-be buyers are equally distracted by their summer holidays.

“So while an increase in seller numbers is a welcome sign of more liquidity in a generally stock-starved market, it has unfortunately come at a quieter time of year.

“Prospective buyers will need tempting with a summer special price or a beautifully finished and presented must-have home, and sellers whose homes tick these boxes then need an estate agent with good marketing skills to promote it effectively.”

Shipside added: “The number of sales being agreed by estate agents is consistent with the same month in 2017 and is holding up well considering the uncertain political background and stretched buyer affordability.

“In fact, there are signs that activity is improving as the year progresses with sales agreed year-to-date now down just 3.9%, compared to 5.4% that we reported back in May. Most regions in the middle and north of Britain have brisk market conditions where buyers eagerly soak up extra supply of suitable property coming to market, and where there is enough momentum to support an increase in prices.

“With less momentum further south, any increase in property coming to market often leads to more property choice and gives buyers more negotiating power. Whilst stock levels are very limited in the brisker market locations, from a national average perspective as we enter the summer holiday period the total stock per estate agency branch is at the highest level for nearly three years.”

The research found having a competitive and realistic asking price from the beginning helps to attract immediate buyer interest and increase the chance of an earlier sale. For those homes not selling, reducing the asking price of their property is a common tactic.

A third of properties currently on the market have been reduced at least once since they first came on to Rightmove, which is the highest at this time of year since 2011.

Shipside said: “A reduction in asking price is often a sign of initial over-pricing by estate agents and sellers, and whilst a price cut can boost buyer interest you have to overcome the negativity that arises when a property has not been snapped up quickly.”

Nick Leeming, chairman of Jackson-Stops, added: “Whilst it is the norm to see more sellers coming onto the market at this time of year there has undeniably been a stronger bounce in May and June this year as many homeowners held off listing their properties due to the unseasonably cold weather in March and April.

“An increase in the number of properties for sale will have to be matched by a corresponding increase in buyer demand if vendors are to avoid reducing guide prices to secure a sale.

“The market is finely balanced at the moment and the latest political uncertainties over Brexit will do little to help build confidence.”