"Too many mothers and fathers do not know what good parenting is and follow the example of Frank Gallagher, the feckless father in the hit Channel 4 comedy, shadow work and pensions secretary Chris Grayling will say.

He will say that the Conservatives must be ready to address the loss of parenting skills, such as the ability to say 'no' to children, to punish them or to offer them affection.

Tory attacks

But he will reject earlier Tory attacks on single mothers, insisting that the party should never again appear to be "at war with lone parents".

"There are millions of devoted lone parents delivering the care and nurture children need, often in challenging circumstances. We want to help lone parents build their lives, not stigmatise them," he will say in a speech in London.

Britain

"I think the parenting challenge we face is much more complex than family breakdown alone."

In many parts of Britain, children fail to learn parenting skills from their own parents - whether single or part of a couple - because they are left largely to their own devices as they grow up, Mr Grayling will say.

Unusual

And he will say that the "inherited knowledge" of how to care for and nurture a child is swiftly lost from communities where the generations pass quickly and 30-year-old grandparents and 45-year-old great-grandparents are "far from unusual".

"I think many parts of our society no longer know how to bring up children," Mr Grayling will say.

Most people

"We live in a country where, in many places, Frank Gallagher-style parenting has become the norm and not the exception.

"There are too many communities where parents no longer know what good parenting is. Where children are largely left to their own devices as they grow up.

"Most people learn their parenting skills from their own parents ... Who else but from your own parents do you learn how to say no, or when to punish, or when love and affection is needed?

"But what happens if that inherited knowledge simply isn't there? What happens if your own parents lacked parenting skills?"

Following on from the Conservative green paper on welfare reform, Mr Grayling is expected to call on the party to take action to revive parenting skills, emphasising the importance of work in helping to structure lives and encourage personal responsibility.