Working parents should be able to claim tax relief on childcare, Conservative leader David Cameron has said.
He said it was "pretty offensive" that a working man could get tax relief on mobile phone bills when a working woman could not if she used a child minder.
He told the National Family and Parenting Institute he wanted to make childcare tax credit simpler and "more user-friendly".
Mr Cameron also pledged to help single parents as well as married couples.
He suggested gay partners who are in civil partnerships should enjoy the same tax breaks as heterosexual married couples.
And he said the Tory "war on single parents" was over.
The Tory leader, a father-of-three, also encouraged fathers to be there for the "magic moment" of their child's birth.
Mr Cameron, 39, said that childbirth could be a key bonding moment or a "missed opportunity which leaves a couple drifting apart".
Mr Cameron was setting out ideas to be looked at by one of the forums he set up to develop future policy.
He said it was "ridiculous" that a working woman could not get tax relief on childcare.
"Tax relief on childcare for working parents would end this unfair anomaly and this is something that our policy review will be investigating," he said.
Making sure working parents get the money "irrespective of the child care they use" was one simple way of improving the current system.
He believed it was better to let parents keep their own money to spend on things they needed, rather than taking it away in tax and then giving it back to them.
Mr Cameron said tackling the issue of childcare would be a "vital part" of Conservative efforts to help lone parent families.
"Looking for, and paying for, childcare is breathtakingly complex, and especially tough for lone parents, parents from disadvantaged groups, and parents with disabled children," he said.
"So I believe that government has a duty to make good childcare affordable. Sadly, our childcare costs are now among the highest in Europe."
Chancellor Gordon Brown's solution - the childcare tax credit - was too complicated, said the Tory leader.
He also proposed looking at how to strengthen couples' relationships with each other, as well as with their children.
He pointed to Australia's "family relationship centres", which offer support for couples.
Mr Cameron also suggested that programmes like Supernanny offered more effective advice for parents than traditional parenting classes.
He warned against forcing people into certain "family norms" - but said that did not mean the Tories should not champion marriage in delivering a stable background for bringing up children.
"This is not about preaching, it's not about religion but about the question of what works," he said.
Labour Chief Whip Jacqui Smith accused the Tory leader of opposing the introduction of paid paternity leave and describing family friendly legislation as "damaging our competitiveness".
"It is Labour that is giving mum and dads more choice over how they balance work and family life through paid paternity leave, extended maternity leave and the right to request flexible working - all measures that are strengthening families," she said.