A couple have been jailed for 14 years for the gross negligence manslaughter of their newborn daughter when they went on the run with her to avoid dealing with social services.

Constance Marten, 38, and Mark Gordon, 51, were sentenced on Monday after being found guilty in July following a lengthy retrial at the Old Bailey.

The decomposed body of their baby, Victoria, was found in a shopping bag in Brighton in 2023. Police had been searching for the couple for 53 days after officers found evidence of a recent birth in a burnt-out car near Bolton.

Passing sentence, Judge Mark Lucraft KC told the couple “neither of you gave much thought to the care or welfare of your baby” and said there had been “no genuine expression of remorse” from either of them.

They were sentenced on the basis Victoria died of hypothermia – both defendants had argued against that during the hearing.

Gordon will serve a further four years on extended licence, the judge said. There was no reaction from either defendant as they were sentenced.

The first trial found Marten and Gordon guilty of concealing the birth of a child, perverting the course of justice by not reporting her death, and of child cruelty, but the jury failed to reach a verdict on the manslaughter charge.

The court heard that, whem Marten was heavily pregnant, they had decided to live off grid to avoid Victoria being taken off them by social care authorities. Their four other children had previously been taken into care.

During the police manhunt that spanned different parts of England once the circumstances of the birth were uncovered, the couple slept outside and took steps to avoid being found, such as taking long taxi rides that criss-crossed the country.

They were eventually located on 27 February 2023, and Victoria was discovered dead two days later in an allotment shed in the Hollingbury area of Brighton.

She had died while the couple were living in a tent on the South Downs in January that year.

In their trial, the couple had said Victoria’s death was a tragic accident after Marten fell asleep holding the baby – but the prosecution called on evidence from experts on hypothermia, one of whom described the conditions the newborn would have experienced living in a tent in the middle of winter.

During a months-long retrial, the judge said the couple tried to “sabotage” and “manipulate” proceedings.

Firstly there were many days when one or other of them claimed illness, dental pain or just tiredness from travelling back and forth to court from their respective jail cells, causing proceedings to overrun by many months.

When in court, both displayed disruptive and unpredictable behaviour, disrespected the judge, were rude to dock officers and would often talk during proceedings.

On one occasion, Judge Lucraft said about Marten that he has “never had that sort of attitude” shown to him by anyone in his 13 years as a full-time judge.

During the latter stages of the retrial, Gordon parted company with his legal team and took on the role of representing himself in court, despite having no legal training.

Disruption continued during Monday’s sentencing hearing, during which the judge told off both defendants for passing notes in the dock. He told them it showed “a complete lack of respect”.

During mitigation, Marten’s barrister Tom Godfrey told the court: “The sorrow that Constance Marten feels is impalpable.”

He added: “She has, ever since an early stage, accepted that her baby died as a result of something she did. That fact weighs very heavily on her conscience and will do so for the rest of her life.”

Philippa McAtasney KC, the barrister representing Gordon during the sentencing, said Gordon had told her “I regret that things happened the way they happened” and that he will “live with this for the remainder of his life”.

During the retrial, the jurors were told of Marten’s privileged upbringing in a wealthy family. They also learned that Gordon had been convicted of rape in Florida in 1989 when he was aged 14.

For legal reasons, this conviction – for which he was sentenced to 40 years in prison and deported back to the UK after serving 20 years – was not made known during the first trial, but was disclosed the second time around.

In August, the Court of Appeal confirmed to the BBC it had received an application on behalf of Marten to appeal against her conviction.