Rightmove yesterday analysed the total number of properties being marketed and which of the three main portals they are displayed on.

It estimated there to be just over 1m homes on the market in total, of which 170,000 are in London. The figures include sales and lettings stock.

Rightmove broke down the count of properties on Rightmove, Zoopla and OnTheMarket, and insists its research is accurate.

It said that Rightmove has 973,951 properties, including 161,043 in London.

Zoopla has 674,683 properties, including 137,981 in London.

OnTheMarket has 311,721 properties, including 59,640 in London.

The analysis, said Rightmove which will be presenting its figures shortly to the City,  excludes overseas and new homes stock, and includes available stock plus those that have been sold subject to contract or are under offer, or let.

Zoopla last night said it has 850,000 properties, as listed on its home page.

It claimed that traffic to OnTheMarket has been “anything but exciting”.

It also claimed that “numerous” agents who cancelled their Zoopla subscriptions are inquiring about coming back.

Quoting web monitoring firm Hitwise, Zoopla said: “On its first day the OTM website attracted only 23,000 visits, with many of these coming from industry participants interested in seeing the website for the first time.

“Since then traffic to OTM has halved daily to 12,000 visits on Tuesday and less than 6,000 visits on Wednesday. This compares to an average of 1.5 million visits per day to Zoopla Property Group’s (ZPG) websites, giving OTM an audience currently under 1% of that of ZPG.

“The data also seems to suggest that those agents who are promoting OTM heavily in place of their own websites in their offices, emails and press ads are not just missing out on a huge audience for their brands from having dropped one of the major portals but are also starting to see their own website traffic hit by effectively diverting their audience to their competitors.”

Lawrence Hall of Zoopla Property Group said: “Our audience and traffic has remained unchanged since the launch of OTM and whilst Mr Springett seems to be taking aim at ZPG as he sees this as the only way for OTM to get a foothold in the portal market, he will soon learn that delivering great products to consumers and excellent value to agents is the only recipe for success in this space.

“Given the hype and media attention surrounding the launch of OTM this week the audience figures to date are remarkably weak when you consider what he has asked his members to give up.

“We are a very data-driven business focused on the value that we deliver to our members. So, rather than making unsubstantiated claims and promises as others seem intent on doing, we will let the numbers speak for themselves as we have always done.

“And we are already seeing numerous agents who cancelled to join OTM inquiring about coming back to ZPG as they are starting to understand the costs of giving up our services.”

OnTheMarket poured cold water on Zoopla’s claims, saying it was “yet another weak attempt” by ZPG “to intimidate agents who have chosen to remove all of their properties and their corresponding advertising”.

OTM added: “The tactics being employed by Zoopla Property Group smack increasingly of a business running scared in the face of a huge loss of support from independent agents.”

Separately, a video featuring Phil Spencer has been released, warning the public to beware of agents who limit or delay marketing.