OnTheMarket has hit back at suggestions that at least four larger agency firms have deserted it to return to Zoopla.

It has also rejected claims in a Barclays report, based on interviews with 100 OTM member agents, that 9% are considering leaving, with a further 35% saying they will review their membership.

OTM chief executive Ian Springett said: “This report is based on a tiny fraction of OTM’s membership, which consists of more than 5,000 offices.

“Only 48 hours ago, William Packer from Exane BNP Paribas published a report stating OTM had demonstrated ‘resilience eight months into launch against initial market expectations of a swift demise’ and its membership base was ‘supportive’.

“The Barclays report fails to take into account the commitment and the drive among estate and letting agents for an agent-owned portal to succeed and provide agents and consumers alike with a credible alternative to the current duopoly of Rightmove and Zoopla.

“Meanwhile, the momentum and support behind OnTheMarket.com are demonstrated by its growing membership, the number of letters of intent received and the level of consumer traffic, which also continues to increase month on month.

“Increasing numbers of agents tell us that OTM is the source of an excellent quality of leads and say this is far more important that the volume of leads, many of which can turn out to be of no value.

“Many agents have also told us they have not felt any adverse impact on their businesses from removing their properties from Zoopla.”

Springett also said of the claim made by online agent eMoov – which cannot advertise on the site – that it was simply an attempt by a detractor to “try to deflect attention away from the fact that support for OTM is continuing to grow and momentum behind our proposition is growing.”