Papua New Guinea's Opposition Leader, Belden Namah, has asked the country's National Court to declare the Australian Government's Manus Island asylum seeker processing centre unconstitutional.
Judge David Canning says he regards the matter as a human rights issue and he will deal with it as soon as possible.
At a preliminary hearing, Mr Namah's lawyer, Loami Henao, said he will ask the court to prevent any more asylum seekers being sent to Manus Island until the case is heard.
He also said he will ask the court to grant him access to the processing centre to talk to asylum seekers.
Mr Henao said a request to visit the centre had been rejected by PNG's chief migration officer.
He said another issue that needs to be determined is whether asylum seekers should be represented in court and, if so, how.
The matter has been adjourned until Wednesday afternoon.