Lord Sugar condemned "claim culture" as he accused a winner of his TV show The Apprentice of lying and taking him to a tribunal "to extract money from me".
Stella English, 34, who won series six of the BBC1 show fronted by the millionaire peer in 2010, is suing him for constructive dismissal.
Ms English, of Whitstable, Kent, said she felt pressurised into taking up a new position at Lord Sugar's internet set-top box company You View.
She told the hearing in east London that Lord Sugar then advised her, in an unscheduled meeting on September 28, 2011, that he would not be renewing her contract and that he told her he did not "give a s***".
Reading out his own statement, Lord Sugar said: "She is a suspicious, untrusting person and one who believes she has always been done down and places blame with others.
"I believe this claim, together with its publication in the media, is simply an attempt to extract money from me."
He said Ms English wrongly believed he was "scared" of articles about him or The Apprentice appearing in the press.
Lord Sugar said: "I seriously believe the claimant is deluded that I'm frightened about newspaper articles and that I would not appear at a tribunal as a witness."
He said Ms English was under the impression he would pay her off to avoid having to attend the hearing.
But he told the tribunal: "I have no intention to pay her any money unless told to do so by the law."
Lord Sugar added that he held strong principles on the issue and had spoken in the House of Lords on "this new wave of claim culture".
He said that within days of Ms English suddenly leaving her job in October 2011, interviews with her appeared in newspapers.
"She was desperate for money," Lord Sugar told the hearing.
That May, after stepping down from Viglen, she told Lord Sugar she planned to write a book and make public appearances, the tribunal heard.
"She was missing the attention that she has previously enjoyed as The Apprentice winner," added Lord Sugar.
He dismissed Ms English's allegation that she had been pressurised into taking the You View job as "total garbage" and her claim that she was ostracised by colleagues at Viglen as "a figment of her imagination".
The entrepreneur also said Ms English's claim that he told her he "didn't give a s***" was another example of her being "deluded".
In an exchange with Philippa Jackson, representing Ms English at the tribunal, Lord Sugar accused his former employee of lying about her version of events in a bid to generate publicity.
"I'm angry because of this, because it's a total lie," he said, when Ms Jackson suggested he appeared angry.
"When I came into the process of this tribunal, I was going to try to be generous to your client, but I've sat here and listened to her over the past two days and there is no other way to describe what she has said than as blunt lies."
Lord Sugar accused Ms English of "writing headlines" for the newspapers by what she has alleged to the tribunal.
He said the September 2011 meeting was amicable and that he had held similar conversations with previous winners of The Apprentice to discuss their future plans.
There was no full-time job available at You View and she had already made it clear she did not want to work at Viglen, Lord Sugar added.
He told the hearing on Wednesday that Ms English had "odd conspiracy theories" and that she resigned for good because she felt "her time in the limelight was beginning to fade".
Ms Jackson said the employment relationship her client had after winning the reality TV show was "a sham" and "a PR construct".
Ms English alleges Lord Sugar did not treat her life and future seriously.
She claims that in her first day of working for Lord Sugar, she was told by Viglen chief executive Bordan Tkachuk: "There is no job."
The hearing, listed to last for seven days, continues.