The alleged affair, which Ms Harrison claims spanned two years, began with flirting following a meeting that the two were present at, she claimed.
"We started flirting and soon after Tim began texting and emailing me for sex," Ms Harrison said.
"I knew he was married. It was never about love. It was about sex and power. He likes having a bit on the side. I found our relationship, if you'd call it that, thrilling to begin with."
She claimed Mr Worner's "sexual proclivities and eagerness" were laid bare in hundreds of texts exchanged between the pair, which Ms Harrison said she destroyed "at Seven's direction".
Ms Harrison alleged the pair's encounters continued, including at Seven-sponsored events such as the Australian Open, until mid-2014 when Ms Harrison claimed she became depressed and began having panic attacks.
Ms Harrison said she received $100,000 as part of a confidentially settlement in August 2014, however was made redundant in a second agreement in November 2014 in which the company offered to pay her $350,000. Ms Harrison said she was never paid the agreed amount.
Her redundancy coincided with an investigation into Ms Harrison's use of corporate credit cards. Seven has stated the investigation was completely unrelated and was merely a random check.
Since making her grievances public, Ms Harrison has challenged Seven to "play out their war of law against me in public now".
Seven has not responded to a request for comment over the affair and Ms Harrison's claims over the legal stoush.
The network last night admitted to the Daily Telegraph that its chief executive had apologised for the relationship that took place before he was in the top job, and said it was a private matter for Mr Worner and his family to deal with.