Nearly half of children in Britain see their parents separating by the time they turn 16, shocking figures have revealed.
It has also emerged that births outside marriage are at their highest level in two centuries.
Nine out of 10 couples now live together before - or instead of - tying the knot. Before the Second World War, it was fewer than one in 30, reports the Daily Mail.
Some 46 per cent of children are born to unmarried mothers, according to research by the Centre for Social Justice (CSJ).
The report says the decline in the traditional family is a crucial factor in the social decay that is blighting Britain.
The authors of the research point to evidence suggesting that in the 1950s and 1960s, only one to three percent of couples cohabited before marriage.
Today, nearly 90 percent of couples live together before, or instead of, getting married.
Family breakdown, the experts claim, is being fuelled by the growth in the less stable relationship of cohabitation.
"Current high levels of cohabitation are a key factor in the rise in family breakdown in our country and this paper shows that we have not been here before," said Gavin Poole, executive director of the CSJ.
"Marriage and commitment tend to stabilise and strengthen families and cannot be ignored. The peculiarly high levels of family breakdown found in Britain are at the heart of the social breakdown, which is devastating our most deprived communities.
"Strengthening families is vital, both to the health of Britain and in ensuring a more socially just society, he added.