There will be a full hearing next week into a baby at the centre of a High Court case taken by Te Whatu Ora over the parents' insistence he is treated with unvaccinated blood.

Both the agency and the parents say the matter is urgent and are attempting to organise mediation before that.

Te Whatu Ora is making an application under the Care of Children Act regarding the baby who needs open heart surgery.

It is asking that the baby be placed under the guardianship of the court.

Te Whatu Ora then wants the court to appoint the doctors as agents of the court for medical care, and the parents agents of the court for all other care.

The agency's lawyer Paul White told the court the baby is getting sicker with every heart beat.

White says under any other circumstance, a child with this condition would have been treated by now.

Supporters outside the High Court in Auckland where Te Whatu Ora is taking a case against parents who are refusing to allow blood from vaccinated people to be used during their baby's life-saving heart operation. Photo: RNZ / Marika Khabazi.

The parents and the baby were present in court for the hearing.

Sue Grey, Lawyer for the baby, says doctors are dismissing the parents as conspiracy theorists and ignoring their concerns.

She told the court they want the best for their child.

The hearing was administrative only and a date for the full hearing has been set down for Tuesday.

Meanwhile, about 100 anti-vaccination protesters carrying placards were outside the court in support of the couple.

About 100 people gathered outside the High Court in Auckland to support the parents. Photo: RNZ.

A supporter of the babys' parents, Sarah McNaulty, says their stance is about having freedom of choice.

"There's so many people lined up to give their blood freely," says McNaulty.

"That is where tyranny starts. When the state provides us with not being able to give blood freely to a patient that needs it."

The Blood Service says it did not keep blood for vaccinated and unvaccinated donors separate and there is no risk from the Covid-19 vaccine.

The health authority earlier told RNZ the decision to make a court application is always made with the best interests of the child in mind and following extensive conversations with the whānau.

It says it knows it can be worrying for parents who have a sick child and who are making decisions about their care.

-RNZ.