David Cameron has vowed to protect children from "ruthless marketers and shameless retailers" in a speech to the Tory spring forum in Gateshead.
Setting out his vision for a "family friendly" Britain, he pledged to double the number of health visitors.
Some Tories had concentrated too much on family structure, said Mr Cameron.
Being family friendly was not just about tax and benefits, but also making the UK a better place to bring up children, he said.
He told party activists being family friendly was "seriously Conservative" - but in the past some on the right had "got families wrong" by suggesting "that the only thing that matters is family structure".
He said the modern Conservative Party was "a party for all families" including single parents - and he argued that politicians had to take a lead in calling for greater responsibility from business.
Citing the campaign by parents to have a children's bed named Lolita withdrawn from sale by Woolworths. he told Tory party members: "Parents want to know that the freedoms they give their children won't be exploited by ruthless marketers and shameless retailers.
"So making Britain more family-friendly means saying yes, we will raise the tax on alcoholic drinks aimed at children and we'll give local communities the power to force the police to take away the licences of the bad retailers who sell it to them.
"And making Britain more family-friendly means demanding that TV producers, magazine editors, music companies, book publishers - all the media businesses accept that what they do really matters to our society.
"Too often, the programmes, articles, music videos and books introduce our children to sex and violence and adult emotional dilemmas at an incredibly early age. It's not right and parents want you to stop it."
It was the "early years" where parents needed the most help, he said. The party has pledged 12 months' leave to be shared by mothers and fathers.
Mr Cameron also pledged to more than double the number of health visitors if the Conservatives return to power, with the £200m cost coming from scrapping plans for more outreach workers for SureStart family centres.
He has stressed that he thinks SureStart is a "good scheme" but spending the cash on health visitors rather than outreach workers would benefit all families.
In his speech, he accused ministers of allowing the ranks of health visitors to go into "freefall" over the last three years, with numbers plummeting by 10% to just 9,000 full-time posts.
With 30% eligible for retirement within the next five years, Mr Cameron says the situation will deteriorate further unless action is taken soon.
David Cameron has been pictured frequently with his family
New parents currently spend an average of just four hours and six minutes with health visitors in their child's first year, he said.
"Instead of more untrained outreach workers, we need more trained professionals who really know what they're doing," he told Tory activists.
"They're called health visitors. Highly-trained NHS professionals who come to your home and build up a trusting, personal relationship with the family."
Mr Cameron denied the policy was an attack on SureStart, saying it was "about making SureStart work better".
The government has reacted angrily to what they claim is an attack on the SureStart scheme - one of Labour's flagship policies.
Children's minister Beverley Hughes said SureStart already "makes a real difference to children's lives".
"David Cameron should support SureStart, not constantly try to undermine it. Scrapping this vital front line service will hit the poorest most," she said.
Mr Cameron also focused on the need to clean up politics at Westminster in his spring forum speech, in the wake of recent scandals over MPs ' expenses.
"Let's not pretend that we're outsiders to Westminster, come to clean things up.
"We've been part of the problem and we need to sort it out from within. That's why we'll bring about a clear change in Parliament. No more MPs voting on their own pay. No more cushy final salary pensions scheme. Clear declaration of expenses and allowances."
Mr Cameron earlier brushed aside suggestions his party was not building up the sort of opinion poll lead it will need to be confident of victory at the next general election.
A poll of polls in the Independent newspaper, analysing the trends identified in surveys over the past few weeks, suggested the Tories were averaging a six-point lead over Labour, down from nine points at the start of the year.
But Mr Cameron told the BBC: "I think we are in a good position. We have got further to go. We have really got to convince people, with all the hard work we do and everything we produce, that we are ready for government."