Primary schools in England are to be encouraged to take children as young as two in their nurseries.
The government wants to ease restrictions and extend opening hours, so parents can leave their children for the whole working day.
Opponents believe it is an attempt to organise childcare on the cheap, and would leave young children in the wrong environment.
June O'Sullivan from the London Early Learning Foundation told ITV News: It's inappropriate and I really feel uncomfortable because it really feels like easyJet childcare.
"You've got a few spaces here and there and you pluck them in and that will be fine - but that won't be fine, because children won't thrive in that environment."
Political Correspondent Libby Wiener reports: