Assange lawyer Geoffrey Robertson said Swedish Prime Minister Fredrik Reinfeldt has created a "toxic" atmosphere that would make a fair trial impossible.
"The Swedish prime minister says Assange is an enemy of the people," Robertson said. "He's made falsehoods in Parliament and the Swedish people will believe him. In Sweden (Assange) is public enemy No.1 as a result of the prime minister's statement."
It wasn't immediately clear which comments Robertson was referring to. Reinfeldt spoke to reporters Tuesday about the Assange case in Stockholm's Parliament building, rejecting criticism of the Swedish justice system by Assange's lawyers. He did not call Assange a public enemy.
Assange, famous for publishing a massive cache of confidential U.S. military and diplomatic documents, is wanted for questioning in Sweden on sex crimes allegations stemming from a brief visit there last summer. Two women have accused him of sexual abuse. He has denied the allegations and described the sex as consensual.
The allegations include the charge that Assange tried to have sex with one woman while she was asleep, which can constitute rape in Sweden, and that he became violent during other sexual acts.
Assange's lawyers have sharply criticized Sweden's justice system, particularly the Scandinavian nation's practice of holding some rape trials in private to protect the identity of alleged victims. The criticism became so pointed that Reinfeldt felt moved to react to charges of unfairness.
"Unfortunately this is what happens sometimes when you describe other countries' justice systems in derogatory ways to defend your client," Reinfeldt told Swedish Radio on Tuesday. "But everyone who lives in Sweden knows that it doesn't correspond with the truth. And we have far-reaching, profound traditions of an independent, well-functioning judiciary in Sweden."
"Let us not forget what is at stake here: It is the right of women to get a hearing on whether they have been exposed to abuse," Reinfeldt added. "We don't know what is true or what is wrong or what the verdict will be."
Reinfeldt declined to comment further on Friday.
Robertson claimed the Swedish prime minister said Assange should be charged with rape and characterized the WikiLeaks founder as opposed to women's' rights, which Robertson called a "pernicious lie."
However, lawyer Clare Montgomery, representing the Swedish government, said the prime minister did not make such comments and Robertson was completely misrepresenting what had been said.
Montgomery ridiculed Assange's claim that the prime minister's statement would make an impartial trial difficult, and focused on the alleged sex crimes, which she said are serious enough to merit extradition.
She described Assange as violent and abusive toward the women, using force in one case to pin one down as he tried to penetrate her against her will.
"It is clear that what Mr. Assange is charged with meets the European definition of rape," she said. "There is no justification for him saying there is nothing in the evidence that can be called violent."
Assange's lawyers tried to adjourn the case to give them time to assemble expert testimony on the impact of the prime minister's comments, but Judge Howard Riddle turned them down, saying he could not tolerate any more delays.
Riddle said the case would be back in court on Feb. 24, when he is expected to give his decision on the extradition request. But he admitted that an appeal was "inevitable," meaning more court proceedings before Assange's fate is decided.
Assange, 39, entered the courtroom wearing a well-tailored dark suit and tie and waved to supporters in the gallery before taking his seat. He yawned several times during the closing arguments and did not show any emotion as his alleged sexual activities were discussed.
Both sides recapped arguments made earlier in the week at Belmarsh Magistrates' Court, with Assange's side arguing that Swedish prosecutors acted improperly and the Swedish government saying it is seeking Assange only after repeatedly failing to question him.
Montgomery said they cannot simply interview him via Skype or other technology in part because they seek a DNA sample.
Assange and his supporters say the case against him is riddled with irregularities, with some alleging it was part of U.S.-led plot to prosecute the WikiLeaks founder or blacken his reputation in retaliation for his spectacular leaks, which have embarrassed U.S. officials.
Meanwhile, Assange is out on bail - albeit under strict conditions - at a supporter's country mansion in eastern England.