Describing vouchers for parenting classes in England as a "nanny state" policy is "nonsense", David Cameron has said.
In three trial areas, those with children aged up to five can get a £100 voucher towards parenting classes.
The PM has also announced a new NHS online information service for parents of very young children.
Labour said it had an "open mind" but schemes needed to be "value for money" and reach a "wide range of parents".
Defending the policy, David Cameron said: "I think this whole debate about nanny state is nonsense.
"Parents want help. It is in our interest as a society to help people bring up their children.
"We're taught to drive a car. We're taught all sorts of things at school. I think it makes perfect sense to help people with parenting."
He denied that a focus on parenting and childcare was a diversion from "big issues" like the economy.
The vouchers are now available from health professionals and on the high street through the chemist Boots.
The government hopes to encourage demand for these kind of classes and "reduce the stigma of asking for information, advice and help with parenting."
In addition, the government is launching a new NHS online service for parents covering areas such as breastfeeding, nappy changing and post natal depression.
Expectant parents or those with a baby under a month old will be able to sign up for text and email alerts providing them with "regular, relevant and tailored" advice including short information films and advice from other parents.
From July, subsidised relationship support services will be available for new parents and those expecting in several trial areas: York, Leeds, North Essex, Hackney, the City of London, Islington and Westminster. The scheme will not be extended to Scotland, Wales or Northern Ireland, if successful.
Mr Cameron said he would have liked parenting lessons himself.
"I've got three, and the youngest is not yet two, and I still sometimes think I would love to have a bit more information about how to get them to do the things I need them to do sometimes," he told ITV1's Daybreak.
However, in 2006 in a speech to the National Family and Parenting Institute, Mr Cameron suggested parents found TV programmes like Supernanny more useful than parenting classes.
"In recent years, there's been an explosion of information about bringing up children: TV programmes like Wifeswap and Supernanny, books and magazines, and online resources," said Mr Cameron.
"These can be more useful than formal options like parenting classes, to which there is often a stigma attached.
"So we should encourage the growth of modern forms of parenting advice.
"Britain's families need Supernanny, not the nanny state."
Shadow education secretary, Stephen Twigg said he would keep an "open mind" on parenting classes but said the government "has hit families with children hard" with cuts to tax credits and Sure Start centres.
He said: "Most importantly, any new scheme must be able to reach a wide range of parents from different backgrounds and provide real value for money."