Lawyers for Julian Assange have called for controversial telephone evidence to be released as they made a fresh attempt to break the deadlock in the rape case brought four years ago against the WikiLeaks founder.

Filing a challenge to the prosecution in the Swedish courts, lawyers for Assange – who last week marked the second anniversary of his asylum in Ecuador's embassy in London – said a recent revision to Swedish law requires evidence held by the prosecution to be made available to the defence.

Text messages sent by the two women plaintiffs were seen by defence lawyers in 2010, but copies of the messages were not issued to them. Assange has claimed that text messages sent by one of his accusers show that she was ambiguous about his arrest and even opposed to it.

"The messages strongly suggest that there is no basis for the arrest and they are thus vital so that he [Assange] can effectively tackle the arrest warrant," the lawyers say in documents filed with Stockholm district court on Tuesday.

The court said the request would be assessed within a few days by judge Bertil Sundin, who declined to comment.

The Swedish detention order that Assange is challenging requires him to be extradited to Sweden to face questioning over the alleged rape and sexual assault of two women there in August 2010.

Assange claims cooperation with the British and Swedish authorities would expose him to an ongoing criminal investigation by the US Department of Justice into WikiLeaks activity.

Sweden's code of judicial procedure was updated on 1 June to conform with EU law, and now includes a provision that anyone arrested or detained has the right to be made aware of "facts forming the basis for the decision to arrest".

"There is material in the prosecutor's possession that we know is to Julian Assange's advantage," said his lawyer Thomas Olsson, based in Stockholm.

"The new law enables her to release that new material, which has been in the prosecutor's possession from the start … We have seen the text messages but have not been able to use them because we could not demand that the prosecutor hand them over as evidence to the court."

The new law was "a little bit of a revolution" in Swedish legal procedure, Olsson said.

Bengt Ivarsson, president of the Swedish Bar Association, confirmed that since 1 June a suspect has had the right to be made aware of "all the circumstances that have influenced a court's decision", so all the papers for the prosecution must be handed over to the defendant.

"The new law gives us more power," said Per Samuelson, another lawyer for Assange in Stockholm, who said they had also written directly to the prosecutor on Tuesday to request the text messages. "In 2011 we were allowed to read them and memorise them, but we do not have the full messages."

ΩThe lawyers also argue that the "severe limitations on Mr Assange's fundamental freedoms" over the past four years are "unreasonable and disproportionate".

They further attest that the arrest warrant should be rescinded because it cannot be implemented, owing to Assange's asylum in the Ecuadorean embassy. "Under Swedish law, if a detention decision is not useful for its purpose, then it must be rescinded," Samuelson said.

Swedish legal opinion at a senior level has swung against the prosecutor's decision not to travel to London to interview Assange, with Anne Ramberg, head of the Bar Association, calling the current impasse a "circus".

Elisabeth Massi Fritz, a lawyer for one of the women in the case, did not respond to telephone and email requests for comment. Interviewed this year, she said her client would wait as long as it takes to get justice in court, even if Assange stayed in the Ecuadorean embassy until the statute of limitations on the case expired in 2020.

The Swedish prosecutor declined a request to comment.