More than 75 per cent of UK estate agents are threatening to remove properties currently listed on the UK's biggest property website, according to an online poll.

The survey, by estateagenttoday.co.uk, found that more than three quarters of estate agents will not be renewing their annual subscription to the site because its fees, which can be as high as £500 a month per estate agent, are considered too expensive.

Should the planned defection go ahead, it would leave Rightmove, which boasts around 20,000 agents and developers, a less reliable source of information for homebuyers wanting to compare properties on the market.

The company, founded by Halifax, Countrywide & Connells estate agencies in 2001, saw estate agency membership fall by 3 per cent in the first six months of this year to 11,984. Its retention rate among estate agents was down to 84 per cent in the same period, which Rightmove attributed to the large number of estate agency businesses leaving the industry.

The poll, which represented 10 per cent of agents on Rightmove, coincides with the growth of rival free property search websites such as Globrix.com, part-owned by News Corporation, parent company of The Times, and Propertylive, owned by the National Association of Estate Agents, due to launch next week.

Experts said that despite the poll results, it is unlikely that many agents would leave Rightmove, which has 90 per cent of all UK Estate Agents listed as members. Simon Baker, editor of propertyportalwatch.com, said: "I don't believe agents will leave Rightmove because of the cold hard reason that it dominates 'eyeballs' online, which equals leads, so to walk away to a free site that has one tenth of the traffic would be marketing suicide."

Miles Shipside, commercial director of Rightmove, said: “Especially in this tough market, there is rightly discussion on the pros and cons of ‘free’ portals and how they can raise adequate revenue to offer an effective service for home movers and estate agents. They will face the challenge that we did initially of investing substantially and consistently over several years."

In the seven years since it was founded, Rightmove has invested more than £100 million. It receives 40 million visitors each month.

Shares in Rightmove were down 5 per cent today, to 228.25p.

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