Lawyers for two asylum seekers and their Brisbane-born child will file an urgent application to the High Court to prevent the family being transferred to a Darwin immigration detention centre.

Baby Ferouz was born in the Mater Hospital at South Brisbane in November, after his pregnant mother was transferred from Nauru due to concerns about her pregnancy.

The Federal Government has told the family, who are currently in detention in Brisbane, that they will be moved to Darwin tomorrow morning.

The family's lawyer, Murray Watt, says forcibly transferring the family is wrong.

"For the Government to forcibly transfer him and his family now after everything they've been through is beneath contempt," he said.

Mr Watt says the baby is entitled to Australian citizenship.

"The real question here is why this baby is in detention at all - Ferouz was born in Brisbane, he has a Queensland birth certificate and he is entitled to Australian citizenship," he said.

"He should not be in detention at all, let alone be moved around like a pawn in some sick game.

"Not only was Ferouz born in Brisbane, he and his family are now settled here in the local detention centre.

"Their doctors are based in Brisbane, they have legal proceedings in Brisbane this month, and yet [Immigration] Minister [Scott] Morrison wants to move them thousands of kilometres away."