The lawyers of Mr Li Shengwu will apply to set aside the court order allowing the Attorney-General's Chambers (AGC) to serve papers on their client in the United States.
The AGC had earlier served papers for contempt of court against Mr Li, who is the eldest son of Mr Lee Hsien Yang and nephew of Prime Minister Lee Hsien Loong.
A pre-trial conference for the case was held at the High Court yesterday, attended by Senior Counsel Francis Ng for the AGC and Mr Li's counsel, Mr Abraham Vergis of Providence Law.
In a statement, Providence Law said it informed the court that it will make an application to set aside the ex parte - or one-sided - order that allowed the AGC to personally serve papers on Mr Li, 32, who is a junior fellow at Harvard University.
Noting that the court papers filed by the AGC exceeded 1,300 pages, the law firm said: "We explained we needed time to address the novel grounds which the AGC relied on to justify serving the papers out of jurisdiction."
The court directed that Mr Li file his application by Dec 22, and the next pre-trial conference is expected to take place on Jan 4.
When contacted, Mr Vergis declined further comment. The AGC did not reply to queries on the issue.
Lawyer Choo Zheng Xi said the case against Mr Li cannot proceed if the application to set aside the court order goes through. If so, the AGC could appeal against that decision to the Court of Appeal, or re-apply to court in a way that is procedurally correct, he said.
Mr Choo recalled that a similar appeal was made in the case of Mr Alex Au, whom he acted for when the socio-political blogger was accused of contempt of court in 2013.
"The judge, at first instance, did not give AGC permission to even start proceedings against Mr Au in relation to one statement of alleged contempt of court," Mr Choo said.
Mr Au was subsequently fined $8,000 for comments that undermined confidence in the judiciary.
Veteran lawyer Amolat Singh said: "By applying to set aside the order, what Mr Li's lawyers are saying is that the service (of papers) could have been improper or defective."
He noted that the court listens to only one party when an ex parte order is obtained.
"Now, Mr Li will be able to put forward his own reasons on why this service may have been defective," Mr Singh said, adding: "If they manage to set it aside, technically, the papers would not have been served to Mr Li yet."
Mr Li previously said he would not return to Singapore to face the contempt proceedings.
The case centres on a July 15 Facebook post in which Mr Li said "the Singapore Government is very litigious and has a pliant court system", and that foreign media had been cowed into self-censorship because of previous legal action.
The post was related to a family dispute over the fate of the late Mr Lee Kuan Yew's home at 38, Oxley Road that spilled into the public sphere in June.
The AGC called the post an "egregious and baseless attack" on the judiciary. It wrote to Mr Li to demand an apology, but he declined, saying his post was private.
Mr Li also contended that the post did not constitute contempt of court when read in context.
He added that he had amended it to remove any misunderstanding, but would not take it down.
Among other things, Mr Li said his criticism was directed not at the judiciary but at the Singapore Government's "aggressive use" of legal rules like defamation laws to constrain reporting by international media.
The AGC received permission from the court to initiate contempt of court proceedings in August.