David Cameron has moved to reassure his traditionalist critics by signalling that a future Conservative government would seek new ways of encouraging couples to marry.
The Tory leader endorsed a party policy report which warns that children from single-parent families are more likely to turn to crime.
The report argues that unmarried parents are more likely to separate than their married counterparts with devastating social effects, including higher rates of offending and drug abuse and poorer school results.
As a senior opposition frontbencher also praised some aspects of the Victorian approach to family life, the party faced accusations that it was planning a moral crusade reminiscent of John Major's ill-fated "back to basics" campaign.
However, the tone of comments from the party's high command will please many older grassroots activists worried by its direction under Mr Cameron, who has attracted criticism for his liberal approach to many social issues.
The head of the party's Social Justice Policy Group, Iain Duncan Smith, today connected the existence of a "growing underclass" in Britain with the increasing number of broken homes.
He painted a grim picture of a society in which family breakdown, reliance on benefits, addiction to drink and drugs, educational failure and debt is coming together in a "vicious spiral, pulling down millions of the most vulnerable people in this country".
Mr Duncan Smith accused the Government of undermining marriage through its tax and benefit policies. He said his group had discovered that 50 per cent of unmarried parents, who he described as the "biggest rising group in child-rearing", split up before their child was five. "We do know that children from a broken home, particularly in these difficult poverty-stricken areas, are something like 75 per cent more likely to fail in education and that leads to problems with drug addiction and failure and dependency," he said.
Mr Cameron welcomed the "powerful and convincing report about the extent of family breakdown and the damage this causes society".
He said: "It underlines my belief that the family is the most important institution in Britain and that if we are serious about tackling the causes of poverty and social breakdown then we must look at ways of supporting families and also supporting marriage so that couples are encouraged to get together and stay together."
He said that all of the party's future policies would be judged against the test of whether they encouraged family life.
John Hutton, the Work and Pensions Secretary, said yesterday: "This looks to me like 'back to basics' all over again."
Meanwhile, Dominic Grieve, shadow Attorney General, called for citizens to have the right to tackle unruly teenagers without fear of prosecution for assault. His comments were seen as a break with Mr Cameron's call to " hug a hoodie".
* "Hoodies are more defensive than offensive. In a dangerous environment, the best thing to do is keep your head down, blend in. When you see a child walking down the road, hoodie up, head down, moody, swaggering, dominating the pavement, think what has brought that child to that moment." - DAVID CAMERON
* "The traditional Conservative vision of welfare as a safety net encompasses another outdated Tory nostrum, that poverty is absolute, not relative. It is the social commentator Polly Toynbee who supplies imagery that is more appropriate for Conservative social policy in the 21st century." - Cameron policy adviser GREG CLARK
* "We will not be promising up-front, unfunded tax reductions at the next election." - GEORGE OSBORNE, shadow Chancellor
* "[Marriage] means something whether you're a man and a woman, a woman and a woman or a man and another man. That's why we were right to support civil partnerships, and I'm proud of that." - DAVID CAMERON
* "The papers claim David Cameron wants us to 'hug a hoodie'. I support that. The only difference between David and me is I would hug them a little harder and a little longer I suspect." - DAVID DAVIS, shadow Home Secretary
* "The Conservative Party should not become a recruiting sergeant for the UK Independence Party." - EDWARD LEIGH, the Tory chairman of the Public Accounts Committee
* "You can argue that our Victorian forebears succeeded in achieving something very unusual between the 1850s and 1900 in changing public attitudes by - dare one use the word - instilling moral codes." - DOMINIC GRIEVE, shadow Attorney General
* "Children from a broken home, particularly in these difficult poverty stricken areas ... are something like 75 per cent more likely to fail in education and that leads to problems with drug addiction and failure" - IAIN DUNCAN SMITH, former Tory leaderReuse content