Long-time Republican political consultant Cheri Jacobus has filed a $4m (£2.8m) lawsuit accusing Donald Trump and his campaign manager Corey Lewandowski of libeling her and harming her professional career after the candidate called her a "dummy."

Trump lashed out at Jacobus after she criticised him on Fox TV early in 2016. Trump tweeted: "@cherijacobus begged us for a job. We said no and she went hostile. A real dummy!"

One of Trump's top aides had courted Jacobus to be the candidate's communications director, but she withdrew herself from consideration after a bad experience with Lewandowski, the New York Daily News reported. The lawsuit includes Facebook messages between Jacobus and former Trump aide, Jim Dornan, who sought to recruit her for the post.

Trump's accusations against Jacobus caused "enourmous damage to her career and reputation", as well as "significant emotional distress" and triggered online abuse, according to the lawsuit.

After the tweet, Jacobus was "inundated with an avalanche of vicious ridicule and scorn," she claimed in the suit. "The attacks by Trump's followers were laced with sexual degradation and pornographic vulgarity," it alleged. "She was depicted in numerous graphic illustrations as an appropriate victim for rape and sexual assault."

As for Lewandowski, he "wrongly and maliciously" said on national television that she had badmouthed Trump because he had denied her a public relations job, according to the suit.

"This is the same person, I'll just tell ya, who came to us on multiple occasions trying to get a job from the Trump Campaign, and when she wasn't hired clearly she went off and was upset like that," Lewandowski said on a January 2016 "Morning Joe" broadcast, according to the suit.

Attorneys for Jacobus sent a cease-and-desist letter after Trump and Lewandowski's comments, but it was ignored, and Trump tweeted again two days after the letter was sent: "Really dumb @cherijacobus. Begged my people for a job. Turned her down twice and she went hostile. Major loser, zero credibility."

Hope Hicks, a spokeswoman for the Trump campaign, said in a statement that the lawsuit had no merit. "This is just another frivolous lawsuit and an attempt to gain notoriety at the expense of Donald Trump," she said.

Jocobus has also had a few choice words of her own for Lewandowski, tweeting in early January 2016 that he was an "unstable, unhinged hothead."