Health campaigners called today for the "breast is best" message to be changed after research suggested it may be failing to convince new mothers.
The Breastfeeding Network said the message suggests breastfeeding is the preferred - rather than the normal - way to feed babies.
It reinforces the view that formula milk is the "standard" way of feeding, with breastfeeding being an added bonus, the charity claimed.
Lesley Backhouse, chair of The Breastfeeding Network, has written to the Department of Health, calling for a change of approach.
"We've got to knock breastfeeding off this pedestal," she said.
"It seems to play straight into the formula manufacturer's hands by encouraging the view that formula is the normal way to feed a baby - whereas nothing could be further from the truth."
She added: "What we should be saying - and are intent on getting across - is that formula feeding is an avoidable health risk to babies."
A Department of Health spokesman said in a statement that "breast is best" was not its slogan, adding: "Breastfeeding is good for babies, good for mothers and incredibly convenient.
"It's crucial that mothers get the support they need to make breastfeeding a success for them and their baby."
Scientific studies have suggested that babies who are not breastfed have an increased risk of childhood obesity and gastrointestinal disorders.
In 2008, researchers from the University of Western Sydney, writing in the journal Maternal and Child Nutrition, said: "Infants who are not breastfed are nearly five times more likely to be hospitalised in their first year due to gastrointestinal and respiratory illness.
"A single early exposure to infant formula may initiate a series of immune responses leading to type 1 diabetes and infants who are not breastfed are much more likely to become adults who are overweight, obese, hypertensive and suffer from elevated cholesterol."
The call by the Breastfeeding Network comes as a poll of 3,000 mothers for Philips Avent found four in 10 mothers struggle to get to grips with breastfeeding their newborn.
Women said they were confused over whether their baby was getting enough milk, whether the infant had "latched on" properly and how often they should breastfeed.
The age at which they should start feeding a child solids also left 36% of new mothers puzzled.
Figures show that eight in 10 women in England start off breastfeeding but only around one in five is still breastfeeding when their baby is six months old.
Professor Terence Stephenson, president of the Royal College of Paediatrics and Child Health, said it supports National Breastfeeding Awareness Week, which is running this week.
He said: "We strongly encourage mothers to breastfeed as there are clear, proven health benefits for babies.
"Breastfeeding provides babies with optimal nutrition, helps protect them from infection in the first six months of life and has been shown to reduce the likelihood of becoming obese in later childhood.
"Nothing comes close to breast milk for the advantages it offers, and we hope that mothers will have the support to make it their first choice for infant feeding."
The Department of Health recommendation that mothers should feed babies breast milk alone for at least six months is based on World Health Organisation (WHO) guidance.