A judge has ruled a baby born in Australia to asylum seeker parents isn’t eligible for refugee status, meaning he and other babies could be sent to Nauru.

Babies born in detention on Australian soil are not able to claim refugee status, a landmark court ruling has determined.

Federal Court judge Michael Jarrett on Wednesday ruled that, in the eyes of the law, 11-month-old baby Ferouz, who was born in Brisbane’s Mater Hospital in November last year, is an unauthorised maritime arrival (UMA).

Ferouz’s lawyer Murray Watt said he will lodge an urgent appeal on Thursday morning on behalf of the child’s family, who remain in detention in Darwin.

The case will also have wide-ranging implications for about 100 other babies born in detention that law firm Maurice Blackburn represents, given they now risk being transferred to Nauru for regional processing.

“As in the case of Ferouz, we will be urgently filing applications on behalf of the 100 other babies we act for, in response to today’s decision and will request that none of these babies be transferred offshore until the outcome of Ferouz’s appeal is known,” Mr Watt said in a statement.

Mr Watt said Ferouz and the other babies still have some hope as long as amendments to the Migration Act, introduced to parliament, don’t get through the Senate.

He’s urged crossbenchers, particularly Palmer United Party (PUP) senators, not to support the laws, which would retrospectively see all babies born to asylum seekers who arrived by boat definitively deemed to be UMAs, including those born in Australia.

The federal government already rejected a protection visa application for Ferouz on the basis he was a UMA.

Judge Jarrett’s decision upheld the government’s view, given legislation defined a UMA as someone who entered the country unlawfully in any way, excluding by aircraft.

The judge also said the law’s aim was to discourage the use of people smugglers.

Mr Watt said while he respected the judge’s decision, the implications meant babies would be sent to live in inhumane conditions.

“I would really hope that, despite today’s decision, the Minister for Immigration (Scott Morrison) and his departmental officials would take a better view than to send potentially 100 babies to inhumane conditions on Nauru,” he told reporters.

Mr Morrison said he was happy with the court’s decision and the government’s new laws would reinforce it.

“It has always been the intention of successive governments that children born to Illegal Maritime Arrivals are taken to have the same status as their parents,” he said in a statement.

Ferouz’s family, including his father, then-pregnant mother Latifar and two siblings, arrived on Christmas Island in September last year, fleeing persecution as minority Rohingyas in Myanmar (Burma).

But laws introduced last year meant asylum seekers who arrived by boat after July 19 were denied the right to claim protection visas.

A separate citizenship application has also been made for Ferouz on the basis he was born in Australia, but was stateless, given the Myanmar government did not recognise Rohingyas as citizens.

Mr Watt said although that application was made more than 12 months ago, immigration officials were yet to make a decision.

“If he does get citizenship, he’s an Aussie kid, just like my own kids,” Mr Watt said.

“The effect of today’s decision and the effect of the laws as they would be amended is that (PUP leader) Clive Palmer could be party to a deal, which results in Aussie kids being taken away to Nauru.”