Whenpoliticians start taking about family values, journalists reach for their chequebooks. I hope David Cameron and Tony Blair, who are both marching into this moral terrain, recall John Major's, "back to basics" initiative in the 1990s. That became "back to my place", as half a dozen Tory ministers who didn't match up to the family ideal were forced to resign.

The education secretary, Alan Johnson, yesterday tried to prevent history repeating itself by insisting that the traditional 2.4 family has no moral superiority over any other form of domestic arrangement.

However, he and David Cameron may have stepped into another moral minefield by calling for action against so-called "deadbeat dads". Feckless fathers don't just live in inner-London estates, and a lot of Labour MPs are divorced.

Johnson's complaint is that fathers spend too little time with their children in marriage and then lose touch with them altogether in divorce. Half of fathers lose contact with their children within a year of separation. Nearly two-thirds lose contact within two years.

The answer is parenting classes for fathers and fathers-only nights at local schools. The Tory leader wants them named and shamed.

Deadbeat dads are taking over from welfare mums as the new social pariahs. An easy target for "right-thinking" politicians. But, as those who work with relationship breakdown will tell you, it is a myth that fathers are walking out on their offspring. Forty per cent of marriages end in divorce, and the vast majority arise, not from paternal irresponsibility, but hostile incompatibility. Just as it is futile to apportion blame to marital breakdown, it is wrong to assume that absent fathers are unconcerned about the welfare of their children. Most fathers are desperate to keep in contact with their kids and to exercise their responsibilities as best they can. Many of them don't get the chance.

Those who seek to demonise absent fathers forget that the majority of divorce actions are taken out by wives. High-profile divorce settlements have provided a potent financial incentive to end relationships on the most acrimonious terms. The children rapidly become pawns in protracted legal battles over custody and maintenance.

The first action of a wife on the point of separation is, understandably, to seize command of the principal asset - the family home. It is generally the father who leaves because there is a legal presumption that the children will remain with the mother.

It's hardly surprising that fathers often find it difficult to maintain contact when access to the children is policed by one of the aggrieved parties to a divorce action - the mother. This almost guarantees that access will be fraught.

The absent parent is easy to blame since they are not there, and this is often accompanied by spurious claims that the fathers are in some way a threat to the stability or even the safety of what remains of the family. I'm not saying that some abusive fathers don't deserve to be placed under legal restraint, but it is very easy to construe the often desperate attempts by an absent father to assert rights of contact as a form of aggression.

Many absent fathers go through real mental trauma through being separated from their children. It is a form of living bereavement. They find that they are written out of their own children's lives and given little scope to form enduring relationships with them.

Men don't get married with the intention of abandoning their children, who are generally the most important thing in their lives, even after divorce. But absent fathers often find that access is infrequent and so hedged about with arbitrary restrictions that they lose heart.

It is easy to say that absent dads should fight harder to keep contact, but it is difficult to do so when arrangements are changed at the last moment and when the only contact is in a soulless "family" room in a council office block.

If absent fathers are going to be brought back into their children's lives then the courts must be prepared to enforce contact orders - at present they don't. Organisations such as the Child Support Agency should make contact a condition of maintenance. And politicians need to engage their brains.

Does it matter if fathers are excluded from the family? Yes, it does. Children need both parents. In some parts of Scotland, half of all children are now living in single-parent families and the father is ceasing to figure as a significant role model, or even a normal part of domestic life.

Children are increasingly growing up in one-sided female-dominated households. They are then cared for by female childminders before they go to primary schools where they will be taught by women teachers. This is particularly damaging for boys, but also affects girls, who come to see men as a race apart. Society cannot function with sexual apartheid.

But demonising dads for this is no more helpful than condemning teenage mums. Both are sexist stereotypes which cloud debate and obscure the reality that, increasingly, marriage is becoming unsustainable.

This is caused, not by feckless fathers, but by a complex range of factors including work pressures, breakdown of community, disintegration of the extended family and the presumption today that it requires two incomes to maintain a decent family living standard.

At a recent conference I chaired on the breakdown of the family, the speakers invariably cited working arrangements as a principal cause of relationship breakdown and anti-social behaviour in children.

The mainly female academics, teachers and social work professionals wanted more support for mothers to be able to look after their children full-time, rather than handing them over to childminders while they went out to work.

No-one wants to put the clock back to the days when women were excluded from careers and chained to the kitchen sink. But women - and men - increasingly want the choice to be able to raise their own children, and they are surely right to do so. If the two-parent family has a future, this is it.

Unfortunately, stay-at-home parenting conflicts with government policy, which is to force lone parents out to work to keep them off benefits. Raising your own children is becoming a privilege of the rich. Attacking divorced fathers is a convenient distraction from the reality that the economic basis of the family has been undermined.

This is much more serious than the scrapping of Married Couples Allowance. The reality is that we are being overwhelmed by family breakdown which is the defining social phenomenon of the age. And deadbeat dads, far from being the cause, are the first casualties.