Couples who live together before getting married are more likely to get divorced, a report has revealed.
The study found that many couples now postpone the decision whether to marry until after living together.
But it also discovered that couples who cohabit before getting married are 15 per cent more likely to divorce than couples who do not first live together.
And those who have previously lived with a different partner before marrying their spouse are around 45 per cent more likely to divorce.
The report also found that unmarried couples who live together when their first child is born are six times more likely than married couples to separate by the time the child is five.
By the time the child is 16, the separation rate for cohabiting couples is still four times as high as that of married couples.
The report said: “Despite the popularity of cohabitation and its relationship to marriage, it is also the case that marriages that start with a period of prior cohabitation are significantly more prone to divorce than those that do not.
“Where there has been a previous cohabitation with a separate person by one or both partners, the likelihood of divorce soars.”
However, the report’s authors added that it was “not clear whether cohabiting couples are prone to separation or whether couples prone to separation tend to cohabit.”
The report, entitled Cohabitation: An Alternative to Marriage?, was produced by the Jubilee Centre – a Christian think-tank.
The report was based on data from 14,103 households and 22,265 adults, and was written by Dr John Hayward and Dr Guy Brandon.
Last November a Government minister warned that children from broken families were suffering poor outcomes and said it was costing the nation up to £100 billion a year.
Iain Duncan Smith pointed to figures showing that children raised in single parent households are nine times more likely to begin a life of crime than those who are raised by both parents.
Mr Duncan Smith said: “It is important that we recognise the role of marriage in building a strong society, especially if we want to give children the best chance in life.”