Health campaigners have called 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.
