Government help is lacking in vulnerable families, the survey claims
Half of Britons feel family life is harder today than 20 years ago with financial pressures weighing them down, the charity 4Children has found.
A third were torn between parental and child care and half saw their extended family just twice a year, it added.
The poll of more than 2,000 adults also found a fifth felt tight finances were the biggest threat to family life.
The findings coincide with the launch of an inquiry by The Family Commission into the tensions behind family life.
Chief executive of 4Children, Anne Longfield, said: "With a growing recognition that family circumstances have a dramatic impact on the outcomes and life chances of children, this study is searching for solutions.
"We know the economic climate is creating real worry and hardship for many.
"Through The Family Commission, families will design their own solutions. Our challenge to all of us is to respond."
The survey by YouGuv found that 27% thought families needed advice and guidance from relatives and the state the most.
A further 61% said families with elderly relatives did not get enough government help, while half said the same applied to people with disabled family members.
The Family Commission's inquiry will explore the support modern families need in terms of benefits and advice.
The commission's chairwoman, Esther Rantzen, said: "My generation has watched family life change beyond recognition over recent decades.
"These new figures show just how hard family life has become with 50% of people unable to rely on families for help and left to muddle through difficult times alone."