Zoopla has returned to the attack on OnTheMarket, sending out Hitwise data apparently showing traffic to OTM fell last week by 25%.

Zoopla described OTM as struggling “to find an audience”.

However, yesterday evening Ian Springett, chief executive of OnTheMarket.com, responded, saying: “Zoopla’s concerns about the growth of OnTheMarket.com at their expense are apparently increasing.

“The traffic figures circulated by Zoopla are inaccurate and we stand by every figure we have previously quoted.

“On March 6 and 7 we passed the two million mark of unique users.

“Contrary to Zoopla’s claims, the traffic levels have remained buoyant throughout March.

“The results of our multi-million pound marketing campaign are continuing to emerge and the property-seeking public are appreciating the faster, cleaner, fresher search experience which OnTheMarket.com offers.

“Ultimately, the property-seeking public and the agents themselves will decide over time which portals deliver the most value. We remain confident in becoming the number two portal by January 2016.”

According to the Hitwise figures sent out by Zoopla, traffic last week to Zoopla was up 4% and to Rightmove up 2%.

Zoopla said that the figures show traffic to OTM has been falling steadily for the past few days, following the end of its six-week launch marketing campaign.

Two months since its launch, far from closing in on market leaders, Zoopla said the gap is now widening.

Zoopla said its own audience “remains 21 times larger than that of OTM, handing a significant advantage to those agents that have stuck with the market leaders”.

Zoopla’s press release continues: “Perhaps more troubling for OTM is the apparent lack of engagement by those visiting its website, with an average of only 1.5 pages viewed per visit last week versus 7.1 on Zoopla, according to Hitwise.

“ZPG’s total consumer engagement last week was nearly 100 times that of OTM with 21 times more visits and almost five times more content viewed per visit.

“Lawrence Hall of ZPG said: ‘We are data and results driven and will leave others to make wild and unsubstantiated claims and promises.

‘It certainly appears that over the past couple of weeks things have gone from bad to worse for OTM with traffic falling notably from an already low base and very low engagement levels per visit.

‘Two months in and the data shows clearly that OTM is a very expensive and ineffective marketing channel at this point.

‘Every day that OTM restricts its members from spending their marketing budgets freely those agents are spending far more and getting far less than they should.

‘That makes those businesses less efficient and competitive and the longer that OTM takes to act in removing the marketing restrictions placed on its members, the greater the damage it is causing to those businesses and the bigger the advantage it is handing to their competitors.’”

Below are the Hitwise charts supplied by Zoopla

zoopla Weekly Audience Hitwise

zoopla Traffic Stats we 22 March Hitwise