Los Angeles (E! Online) - According to Zeta Graff, coming down with a case of the jail jitters is right up there with the Twinkie defense.

The diamond heiress and sometime actress is lashing out at Paris Hilton's claim that she is too "emotionally distraught and traumatized" in the wake of her jail sentence to participate in a $10 million slander trial that was due to start this month.

Graff filed suit against Hilton back in July 2005 alleging the celebutante spread lies about Graff to the New York Post. Now, Graff is taking issue with the Simple Life star's successful motion to postpone the trial to August, saying that if Hilton is of sound enough mind to continue clubbing despite her encroaching incarceration, she should be more than ready to head to court.

"If Ms. Hilton was nightclubbing on Saturday night, she should not have been representing to the court on Monday morning that she was unable to participate in the trial," Graff said in a statement issued through her lawyers.

"Ms. Hilton should be required to explain her actions and account for them. Under the law, even Ms. Hilton is supposed to be held accountable for her actions."

On Monday, Dr. Charles Sophy, a psychiatrist who has treated Hilton on and off for the past six months, testified in Los Angeles Superior Court that the 26-year-old was not quite ready for the rigors of a trial. Sophy claimed that Hilton's May 4 sentencing to 45 days in jail left her too upset "to respond to examination as a witness or provide any significant input into her defense." (View Sophy's declaration.)

Furthermore, Sophy asserted, forcing Hilton to take the stand could "exacerbate her current mental condition."

Judge Linda Lefkowitz ruled in favor of postponement, saying that Hilton would not be compelled to give testimony May 21 as originally scheduled and that the trial would instead be pushed back to Aug. 22, well after Hilton completed her sentence.

Graff is suing her fellow socialite for allegedly spreading "vicious lies" to the Post about an altercation at London's Kabaret nightclub in the summer of 2005.

According to a gossip item in the newspaper, Graff, Hilton and Hilton's then fiancé Paris Latsis, who had previously dated Graff for two years before taking up with Hilton, all showed up at the club. Graff, the item continued, went "berserk" after seeing her rival and attempted to strangle Hilton and the steal her $4 million diamond necklace.

In a final blow, the Post reported that the necklace had been on loan from the jeweler Graff, owned by the heiress' ex-husband, Fran?ois.

Graff has denied the entire report. Instead, she claims that after arriving at the club she was approached by Hilton, who reportedly said, "I'm going to destroy you," before attempting to have Graff thrown out of the hotspot.

Former Hilton publicist Rob Shuter has backed up Graff's side of the tale, saying in a deposition that Hilton asked him to help plant the story and that all quotes from the article, which were attributed to several people, had all been dictated to him by Hilton.

There was no comment Friday from Hilton's current publicist, Elliot Mintz.

Graff's letter to the court came as Hilton dropped her appeal of her jail sentence, effectively guaranteeing that she will spend just over three weeks in "special needs housing" at the Century Regional Detention Facility, isolated from the general inmate population.

Hilton must turn herself in to start serving the 23-day sentence by June 5.