Another journalist has revealed that he has heard senior Tories describe activists as "swivel-eyed loons".
The Newsnight presenter Jeremy Paxman, said that he had been present when high-ranking Tories had used the term to describe local party members.
His disclosure further undermines attempts by the party to shut down the affair which has caused deep divisions in the Conservative Party amid continuing rows over Europe and gay marriage.
Speaking on Newsnight last night Mr Paxman asked a young Tory activist Binita Mehta: "What about this swivel-eyed loon[s]…that such language can be used by people near the centre of the party about people who get the party elected?"
He then added: "I have heard senior members of your party talking about local activists in these terms."
At the weekend two newspapers revealed that a member of David Cameron inner circle had described local party associations as "swivel-eyed loons". The party co-chair Lord Feldman has admitted to speaking to the journalists but denied he used the phrase in conversation.
The Financial Times has also reported that Mr Cameron "tells colleagues that anyone who wants to talk to him about the EU is 'swivel-eyed'.'"
In an attempt to limit the damage caused by the affair he attempted to assure party members in an email that neither he nor his inner circle would ever "sneer" at them.
Mr Cameron did not refer explicitly to the "mad, swivel-eyed loons" remark, but insisted that he admired and respected his party's activists.
"I am proud to lead this party. I am proud of what you do," he said.
"I would never have around me those who sneered or thought otherwise. We are a team, from the parish council to the local association to Parliament, and I never forget it."
Mr Cameron also tacitly addressed claims that he surrounds himself with a privileged elite by recalling his own work for the party in his 20s, describing himself as just "one of the volunteers" on a local council campaign.
He wrote: "Since then I have met thousands and thousands of party members. We've pounded pavements together, canvassed together and sat in makeshift campaign headquarters together, from village halls to front rooms."
Mr Cameron also acknowledged his differences with party colleagues, but promised to respect their views. He said: "Does that mean we will agree on everything? Of course not. The Conservative Party has always been a broad church and we must remain so today."
At the same time a Tory MP today suggested his own anti-European Union colleagues were also “swivel-eyed”.
Gary Streeter, who represents South West Devon, wrote an article for his local newspaper warning that people would not vote for a divided party.
“In the past few days my party has given a pretty fair impression of being not just divided, but obsessed with a single issue and heading for internal chaos,” he wrote.
He then added: “Over the amendment to the Queen's Speech on Wednesday (on a European in/out referendum) I recognised once more the familiar glint in the swivelled-eyes of the purists who are prepared to sacrifice all to get Britain out of Europe.
“No matter that we wreck our chances of winning next time so long as we get the right policy: a policy that presumably we can contemplate lamely in opposition as we watch a Labour-led government bend the knee to Brussels.”