COT death campaigners said there was "still no evidence" that baby boxes help to reduce infant mortality as midwives called for them to be given to all new babies across the UK.

The Royal College of Midwives said it now backs the universal roll-out of baby boxes, saying that it believes they could help reduce unsafe sleeping practices - such as parents sharing beds with newborns - particularly in poorer areas.

Co-sleeping has been identified as a key risk factor for cot death because it increases the chances of accidental suffocation.

Rates are also higher among babies whose mothers smoked in pregnancy, who are not breastfed, are low birth-weight and whose parents smoke, drink or abuse drugs.

Scotland became the first part of the UK to begin offering all mothers the Finnish-style baby boxes, which can double up as a cot, in August 2017.

The initiative is also being piloted by some parts of NHS England, but not Wales or Northern Ireland.

Gill Walton, chief executive of the Royal College of Midwives, said providing them to all parents regardless of wealth would "provide a more equal start to life for the baby".

She added: “The Scottish baby box contains a number of very useful baby items that can support the health and wellbeing of new babies including an electronic thermometer, a baby carrying sling, a bath thermometer and a range of clothing.

“Most importantly by enabling parents to give their babies a safe sleeping space, baby boxes may reduce unsafe co-sleeping or babies sleeping in an inappropriate place such as a sofa.”

However, Francine Bates, chief executive of cot death charity the Lullaby Trust questioned whether universal baby boxes would be the best use of NHS resources.

She said: "We recognise that for some parents, who do not have a cot or Moses basket for their baby, a box may be a better alternative than co-sleeping in hazardous circumstances, such as on a sofa.

"We also recognise that the aim of some of the Baby Box schemes is to reduce inequality and give all babies the best start in life.

"However, the concerns we raised last year about baby boxes remain valid.

"It is still not possible for baby boxes to fully comply with safety standards, as there is currently no specific standard for the use of a cardboard box as a sleeping place for an infant.

"Additionally there is still no evidence directly linking the use of a baby box with a reduction in infant mortality or SIDS [sudden infant death syndrome].

"Given current pressures on public health budgets, we question whether the call to introduce the scheme across the country is the best use of resources to reduce infant deaths."

The Scottish Government faced a backlash from researchers after initially touting baby boxes as having been linked to a reduction in cot deaths in Finland, where they were first pioneered in 1938.

Academics stressed that other factors such as the introduction of antibiotics, vaccines, improved nutrition and prosperity, and a huge increase in attendance for antenatal care and education - a condition attached to receiving a baby box - were more likely to have been responsible for the fall, rather than the box itself.

In New Zealand, where a shallower type of plastic baby box known as a pepi-pod or a woven alternative called a wahakura, was targeted only to at risk groups including the Maori community - who traditionally co-sleep with infants - there was a 30 per cent drop in cot deaths between 2010 and 2014.

Minister for Children and Young People Maree Todd said: “Scotland has led the way in the UK with our roll out of the Baby Box, demonstrating that, as a society, we value each and every child.

“These boxes will help tackle deprivation, improve health and support families.

"Feedback from parents and carers has been overwhelmingly positive, and as we approach a year since the Baby Box was first introduced I’m delighted that the RCM recognises the real impact they are having on the lives of babies and their carers across the country.”