Paul Boateng, the Home Office minister promoted after resignation of the former Welsh Secretary, said the Green Paper on the family would not be "moralistic".
The consultation paper to be unveiled on Wednesday by Jack Straw, the Home Secretary, was intended to start the biggest debate about the institution of the family for a generation. But the announcement could well be overshadowed by controversy over ministers' private lives.
Mr Boateng said family policy could not be made a "no go" area because of "foibles and frailty of human nature and sexuality - it's got to do with the day-to-day business of making families and family life work."
He continued: "The family is the building block of society; it's a child's bridge into "successful education, good health, and development. It's society's front line against disorder and crime.
"It's an intensely private institution and one has to respect that but it has important public consequences. We have to be there supporting the family - but not in a judgemental way."
The Green Paper will suggest a minimum 15-day cooling-off period for couples marrying in register offices, similar to the publishing of banns in church.
During this time, couples would be asked to take counselling on the importance of marriage. The changes, giving an enhanced role to the registrar who would advise the couple on marriage before the ceremony, would need legislation.
Other ideas include persuading all couples to make pre-nuptial agreements, which judges would have to obey in divorce cases; a helpline for stressed parents; changes to the tax and benefit system to support couples with children; and a bigger role for grandparents in helping couples cope with their children.
The Home Secretary will argue that grandparents are an "unused resource" who can provide advice as well as practical support. "Grandparent mentors" will be encouraged to provide good examples to children whose own parents are failing to bring them up properly. Schools will be asked to encourage the elderly to contribute to lessons - particularly as examples of "living history".
Pensioners will also be asked to volunteer to help in the local community. And local authorities will be told to consider the need for grandparents to be near their children when allocating housing.
Meanwhile, the Labour Party executive in Wales will meet tonight in the hope of ending the Ron Davies scandal by choosing a successor for the leadership of the party in Wales.
The former Welsh Secretary's humiliation continued yesterday as lurid claims of gay sex at a startling array of locations did little to shed light on what happened last Monday night.
Mr Davies, whose mental state is causing concern among his friends, issued a firm and indignant denial of claims that he had had casual sex with men in woods, car parks and public toilets.
He said in a statement: "The fact that I have acknowledged a serious lapse of judgement in a particular situation is not an excuse for the media to pay money to any liar who comes along and claims to know me."