A newborn baby who died after being taken to live in a tent in wintry conditions would still be alive had it not been for her parents, prosecutors have said.

Closing the case against Constance Marten and Mark Gordon on Monday, Tom Little KC said Marten had told “big, fat lies” throughout. He said the child, Victoria, did not stand a chance during her short life.

“Lies fell from [Marten’s] mouth like confetti in the wind when she gave evidence,” he told the jury. “Baby Victoria would still be alive if it was not for the actions and inactions of these two defendants. Nobody else is to blame, are they?”

The couple’s four older children had been “lawfully and properly” taken into care, Little reminded the jury.

“Everyone can and should be able to see that – apart from Constance Marten … in the real world, they caused the death of baby Victoria,” he said. “How they did it and when they did it are critical questions. But be in no doubt about the question of causation.”

He said Victoria, whose body was found by police in a bag in a shed, was a “freezing cold baby girl with just a single babygrow and one vest”.

Turning to the defendants, the prosecutor said: “This was a self-absorbed relationship between two selfish and arrogant individuals, and caught in the middle of that toxic relationship was a baby that was manifestly not being cared for properly, manifestly not being looked after properly.”

He said Victoria was heard crying on two nights in January when it was “bitterly cold”, at least a week after Marten claimed she had died. Little added: “In her very short life, baby Victoria did not stand a chance. That is the cold, hard, brutal reality of this case. There is no point in soft-soaping it.”

Marten and Gordon have both denied their daughter’s manslaughter, with the former arguing in her evidence to the jury that they felt forced to live off-grid for fear of the baby being taken into care, and that she had done nothing but show her daughter love.

The couple abandoned their car after it burst into flames near Bolton, Greater Manchester, on 5 January 2023 and were finally arrested in Brighton on 27 February; days before Victoria’s body was found.

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 Old Bailey trial continues.