John McCririck was not included in a revamped Channel 4 Racing programme because he was seen as an irritating "comic act" who brought a "farcical tone" to shows, a tribunal has heard.
The 73-year-old pundit - known for his flamboyant clothes, tic-tac gesturing and gold jewellery - believes he was "sacked by anonymous suits and skirts" because of his age.
But Jamie Aitchison, the commissioning editor for sport, at Channel 4, said the decision to axe McCririck was taken because his "pantomime style" did not fit with a vision for a more serious and inclusive show, and had nothing to do with his age.
In March 2012 the broadcaster landed the rights to air all UK horseracing events for the following year, including "Crown Jewel" events like Royal Ascot and the Grand National, and Channel 4 saw it as an opportunity to freshen up its racing coverage and appeal to a wider audience.
McCririck - who is taking the channel and TV production company IMG Media Limited to the tribunal - was seen as "unappealing and irritating to many current and potential viewers", according to Mr Aitchison, so was cut from the new line-up led by Clare Balding.
Mr Aitchison, who has worked previously as a producer on BBC and ITV sports shows, said in his witness statement of the former show: "I and others at Channel 4 felt that, although its coverage catered well for a contingent of dedicated horseracing fans, it was niche and non-inclusive at times.
"Channel 4 set out to create a tone that was a little more serious, measured and inclusive.
"None of the decisions taken in respect of who to invite and who not to invite to be in the on-screen team for Channel 4 Racing from 2013 were taken on the grounds of their age, or indeed for any reason other than merit, including the decision not to invite John McCririck to be part of the team."
Mr Aitchison, who gave evidence to the tribunal today, said in his witness statement that concerns over McCririck's style were supported by audience surveys, press coverage and viewer complaints.
"John McCririck was considered to have a 'pantomine style' of exaggerated delivery, which was incongruous with the more serious, measured and journalistic style proposed for the programme from 2013," he said.
The Channel 4 executive said the pundit's "exaggerated tone and style, and propensity to offend was out of step with the vision for the programme, and also unappealing and irritating to many current and potential viewers".
Jennifer Eady QC, representing McCririck, put it to Mr Aitchison that viewers of Channel 4 Racing were considered "old and downmarket", and he said he agreed "to a certain extent".
However, the executive denied that the broadcaster's attempt to diversify their audience meant employing "young and upmarket" presenting talent.
The disagreement arose when Ms Eady asked Mr Aitchison about some notes made by Channel 4's director of creative diversity, Stuart Cosgrove, during a pitch by IMG to win the contract to produce the new 2013 show.
Mr Aitchison told the tribunal that his boss's "young and upmarket" notes in a margin were "TV and advertising speak" and referred to the potential audience such a programme would attract, rather than its hosts.
He said while viewing figures were important, it was not the be-all and end-all, and he argued that a drive to attract a wider audience did not necessarily mean attracting a younger audience.
"We want to produce programmes which we are happy with," he said.
Asked by Ms Eady if he recognised that sometimes unpopular personalities boosted ratings, like Simon Cowell, Mr Aitchison said he did but that it was a matter of taste and opinion.
"I don't find Simon Cowell entertaining," he said, "but it's a subjective view."
Ms Eady put it to Mr Aitchison that Channel 4 chose to go for IMG's bid because the firm made it clear in its presentation that it would employ younger presenters.
Mr Aitchison told the tribunal that all the production firms bidding for the contract to make the 2013 programme had scaled back - or axed completely - McCririck from their pitches.
He said he had been advised by senior executives from across the industry not to use McCririck on the new racing show.
"Not one of those companies came back to Channel 4 and said 'we would like to use John McCririck as a betting pundit in the afternoon'," he said.
"They all realised that this terrestrial contract was not great for John McCririck.
"So picking out individuals seems, at this point, a bit disingenuous."
Mr Aitchison added: "As a broadcaster we had a resounding 'no' from the entire industry.
"I was considering John for another role at this point, but everybody else had said 'no'.
"I would be foolish to ignore that kind of expertise."
Mr Aitchison told the tribunal that although McCririck had appeared on BBC's Newsnight and Sky News, many viewers would be more more familiar with him as a reality TV contestant than a serious racing journalist.
"The lines are so blurred between the Reality TV John and the Journalist John that the public find it difficult to separate the two," he said.
"I'm saying that when John is on BBC, there's no doubt that a large proportion of the people watching that programme will see him as the man who appeared on Big Brother."
Mr Aitchison said in his witness statement that McCririck's reputation had been affected by his "notorious appearances" on a Celebrity Big Brother and Celebrity Wife Swap.
"As a result, he was seen by many as a comic act, rather than a serious horseracing journalist," the executive said.
Mr Aitchison also said McCririck's idiosyncratic style did not fit with the new format of the show.
In his witness statement he said: "His over-exaggerated gestures and facial expressions to camera alongside occasional extreme views on often controversial subject riled viewers and colleagues alike.
"John's nicknames for women contributed to a wider reputation he established for among sexist comments and other bizarre behaviour through his appearances on reality television programmes."
He said McCririck liked the limelight so much that he hogged the camera when he was on Channel 4 Racing, putting himself before his co-presenters.
"He tried to maximise his time on screen and therefore limiting that of others, particularly Tanya Stevenson, the betting pundit he worked with," he said.
Ms Eady asked Mr Aitchison if he had ever told him to change his broadcasting style to fit in with Channel 4 Racing's vision, like waving around his arms less or dressing differently.
The executive replied that if McCririck had changed any of those famous characteristics, he would lose his identity.
"If you chopped off John McCririck's arms to stop him doing tic-tac, he wouldn't be John McCririck," he said.
Mr Aitchison said in his witness statement there were "clear reasons" to end McCririck's contract "which were in no way related to his age".
He added: "It is simply not the case that we appointed a young on screen team or that we did so to attract younger viewers, as he alleges."
The tribunal also heard from Philip Davies, joint chairman of the All Parliamentary Group for Betting and Gaming.
In support of McCririck, he said: "I can't think of anybody who is more on top of their game, or who's more suitable for the role. Absolutely not."
In his witness statement he said: "I am also of the view that it was a catastrophic mistake when he was dismissed from presenting Channel 4 Racing."
The tribunal will resume at 11am tomorrow, when Graham Fry, the managing director of IMG Media, is expected to give evidence.