Fugitive aristocrat Constance Marten was twice warned of the dangers of falling asleep with a baby before the death of her newborn daughter, a court has heard.

Marten, 36, and her partner Mark Gordon, 49, are accused over the death of baby Victoria while they were on the run from authorities last year.

Their Old Bailey trial has heard how they lived in a tent off grid on the South Downs in a bid to keep Victoria, after their four other children were taken into care.

Days after they were arrested last February, Victoria was found dead inside a Lidl bag for life in an allotment shed in Brighton, East Sussex.

Marten went on to tell police that Victoria had died after she fell asleep in a tent while holding her under her jacket.

On Tuesday, a series of agreed facts were read in court detailing Marten’s history with social services and advice she was given about another baby, referred to as Child FF.

Care professionals explained to Marten the risks of falling asleep with the baby on her, including suffocation, overheating and positional asphyxia.

It was explained: “Babies are more delicate and vulnerable and their airways can easily become blocked when placed in certain positions, especially if they are sleeping on an adult’s chest.

“This increases the risk of sudden infant death syndrome (SIDS) or accidental suffocation.”

Marten was warned that positional asphyxia could be “extremely dangerous”, the court was told.

The defendant promised to abide by the advice and not cause any harm to the baby.

Marten was told of the “crucial importance to place (Child FF) in the Moses basket for sleep, rather than allowing herself to doze off with the baby on her chest”.

These concerns were raised a second time, with a social worker noting: “Critical dangers of falling asleep with a baby on one’s chest were firmly raised to Constance who once again stated she understood the risk and would take this on board.”

A social worker explained to Gordon there were concerns about the lack of preparation for Child FF’s birth.

Gordon appeared to accept some concerns but maintained that everyone had the right to choose how they live and they should not be penalised for having a lifestyle that was not “mainstream”.

Previously, concerns had been raised when Marten presented at a hospital six months pregnant having sought no NHS antenatal care.

At the time, she said that she and Gordon had been living in a campervan.

Months later, social services issued a national hospital alert to locate the couple.

When Marten went into labour with Child FF, she and Gordon gave false names at hospital, the court was told.

She claimed she had travelled to “avoid her family”, spoke with a “fake Irish accent” and claimed to be from the travelling community.

After their real identities were established, Marten told social workers they had been living in a campervan after being evicted from a flat.

A care professional said social services “had a number of concerns, including falsifying of names and that Ms Marten and Mr Gordon had been living in a tent”.

I explained to her that it was winter, the conditions were freezing and the cramped space would be wholly inappropriate for a baby to live in

Marten said it had been her idea, that she would engage with care professionals and her child was her priority.

However, she was informed: “Some babygrows and nappies is simply not enough for a newborn baby to be safe.”

Marten was advised to reach out to her family and try to get housing but “due to her homelessness and inadequate preparations for a baby, a court order would be sought if she were unable to establish a suitable home for herself and (Child FF)”.

Social workers found Marten’s tent was “festival-style” and unsuitable for sleeping in during cold weather.

After visiting the tent, a social worker spoke to Marten about the “unsuitability and discomfort” of their situation.

The social worker stated: “I explained to her that it was winter, the conditions were freezing and the cramped space would be wholly inappropriate for a baby to live in.”

Marten accepted it was “challenging” but made clear that she and Gordon had an “alternative lifestyle” and not to judge her for it.

The social worker explained her “primary concern” was the wellbeing of Child FF and it was their role to assess the risk.

The court heard an interim care order was made for Child FF, who was placed in temporary mother and baby placements with Marten.

The couple went on to have three more children and “interacted well” with them during supervised contact sessions.

But their attendance was “inconsistent”, leaving the children distressed and unsettled, the court heard.

One of the children became quiet and withdrawn, telling staff: “Mummy and daddy cancelled again.”

The child was described as “inconsolable” when the parents failed to turn up at the contact centre.

Jurors heard of an incident of domestic violence in 2019 and a judge found a “risk of harm to the children by being exposed to physical violence between the parents”.

All four children were made subject to care and placement orders in January 2022.

Giving evidence by video link, paediatrician Dr Gaurav Atreja said keeping a newborn baby in a tent in temperatures of between 5 to 10 degrees Celsius “can be fatal”.

Prosecutor Tom Little KC asked what the risks were to a baby placed inside a jacket with the parent sitting down.

Dr Atreja said: “If mother goes to sleep she can bend over the baby and the baby can be smothered.”

The court was told cause of Victoria’s death was “unascertained” due to the condition of her body.

The defendants, of no fixed address, deny manslaughter by gross negligence, perverting the course of justice, concealing the birth of a child, child cruelty and causing or allowing the death of a child.

The trial continues.