They will reject his assertion that the political editor's behaviour at an event earlier this week was "tantamount to assault".
If TV3 decides to reply to the complaint by writing to the Taoiseach, it will drag him directly into the row
He may then have to outline his version of events and whether he believes he was the victim of an assault.
It is also understood that TV3 are considering whether to make a counter-complaint against Mr Kenny's €168,000-a-year political advisor Mark Kennelly.
Witnesses say he "barged" across the reporter as she tried to press the Taoiseach on Tanaiste Eamon Gilmore's statement that same-sex marriages should be legalised.
Around 20 journalists were present during the incident outside the National Library, which was also captured by an RTE's television crew.
A source said: "Ursula is rattled by this. She put her question to the Taoiseach and he didn't seem to want to answer but there was definitely nothing that could be described as an assault."
Government Press Secretary Feargal Purcell complained to TV3 after a 'doorstep' interview descended in a farce.
The Government Information Service (GIS) says members of the media acted in an "aggressive" manner towards the Taoiseach.
Several reporters who were at the event where Mr Kenny was asked about his view on same-sex marriage have told the Herald that the GIS was extremely disorganised.
"The blame can be laid squarely at the door of GIS. Everybody left in a state of confusion," said one reporter.
"It [the National Library] was right next door to Leinster House so they were guaranteed a big turnout of media.
"There is a narrow entrance so there was no way that the Taoiseach could get by. Ursula asked the first question in her usual manner and he seemed to try veer around her but bumped into a flower pot."
Another said: "It's a stupid complaint. This has never happened before. It's a bit much calling all the journalists a 'collective disgrace'."
In his complaint to the press gallery, Mr Purcell said: "Put simply, the collective behaviour of the journalists in attendance was disgraceful.
"As the Taoiseach's representative I am informing you that there is no excuse for this unnecessarily aggressive approach to interviewing him which was both disrespectful and unacceptable."