Every government needs a story to tell and David Cameron’s should have us cooing around the hearth. The family is to be the linchpin of the Conservative party’s thinking as it heads towards the next election and in an impassioned speech last week to mark the 70th birthday of Relate, the marriage counselling service, Cameron began setting out his stall.

We already know that the Tories are proposing a £20-a-week tax break for married couples, but it appears that Cameron’s vision of a “family-friendly” Britain goes far beyond the usual Tory territory of rings on fingers as the answer to social ills.

The question, “Is it helpful for the family?”, will be at the forefront of every policy decision he makes, Cameron declares. As a hands-on dad, he recognises the “pressure points” that come with a combination of children and two working parents: even as prime minister he would demand the right to a work/life balance.

What does all this rhetoric mean in practice? After all, we’ve had 10 years of a Labour government accused of being a nanny state for its desire to tell us how to run our lives. Do we really want more of this from the Tories?

They seem to think we do. Maria Miller, shadow minister for the family, is hard at work assessing everything from flexible working for parents of children aged up to 18 to the introduction of Australian-style “family relationship centres” designed to shepherd couples through divorce.

A Cameron government would train an additional 4,000 health visitors and the party is considering doulas – birthing companions, previously the preserve of the affluent middle class – to attend every new mother. Even transport policy (how long does it take you to travel home from work?) will be looked at in terms of its impact on family life.

Putting family at the heart of political thinking is a riskier strategy than it seems. For one thing, families tend not to behave the way governments want them to – the last tax breaks for married couples, in the 1970s and 1980s, coincided with the fastest shift away from marriage of the past century.

For another, what appears to be a perfectly sensible and cohesive policy can have a horrible ability to blow up in your face. Labour’s Sure Start scheme, intended to give deprived children a head start, is now widely seen as an expensive, politicised piece of social engineering that has had scant impact on its target group.

“Where Cameron has been clever has been in associating the Conservatives with quality of life, relationships and family life, and in trying to expose that as a weakness of the current government,” says Graeme Cooke, researcher in social policy at the Institute for Public Policy Research.

“Labour have actually done quite a bit in terms of extending maternity leave and people’s right to request flexible working, but it hasn’t added up to a ‘story’ on the family. There’s a reluctance to talk about relationships and the importance of relationships for fear of sounding moralising and judgmental.

“Cameron has done it very well, but now comes the difficult bit, the specifics. The tax break, for instance. There’s no evidence that £20 a week would have any effect on people’s decisions to marry and in fact Cameron doesn’t claim that’s what he thinks it would do, either. It’s a signal. But at £3 billion a year it’s a very expensive signal.”

One can only assume that Cameron thinks it is worth it: he sees support for family life as the key to repairing the “broken society” exposed by research by the Centre for Social Justice, a think tank headed by Iain Duncan Smith, the former party leader. The CSJ has flagged up family breakdown as a key factor in child poverty, educational failure and street violence.

“We’ll never get to the heart of the big problems we face, from crime and antisocial behaviour to welfare dependency and educational failure, from debt and drug addiction to entrenched poverty and stalled social mobility, if we don’t help the family to do the vital work it does in bringing up children,” Cameron said last week.

He also wants to tap into the daily stresses that afflict every parent, such as “the gauntlet you have to run at the checkout, with endless pushing of chocolate and sweets”. And he added: “For many parents, today’s world can seem incredibly hostile. There are times when each shopping trip, advert break, magazine, film, TV programme or music video seems to conspire against you.”

Keeping parents together is the key. Family relationship centres would play a vital role in counselling unhappy couples or helping them, if they decided to split up, to put their children’s interests first.

In Britain, you either divorce amicably and make your own custody arrangements or fight your way through the courts. The new centres hope to offer a middle way.

“Before Christmas we saw a family in terrible disarray: the father wanted to see the children, the mum was really resistant. So we got her into the office and showed her films about the impact of conflict on children,” says Jo Cavanagh, who runs a centre near Melbourne. “We got some points of agreement and she actually invited him to see the children on Christmas morning.”

The Conservatives might look at making such counselling a prerequisite of divorce. “I have a deep concern that people move forward to divorce or separation without being given all the options,” says Miller. “I would like to see more support for families to stay together.”

Additional reporting by Paul Ham in Sydney

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