The number of men and women marrying in the UK has fallen to a record low, official figures show, with the rising costs associated with tying the knot cited as one possible factor.
Experts also suggested many people are focusing on other priorities such as education, starting a family or buying a house.
Figures for 2015 show rates were the lowest since data collection started in 1862, with 21.7 marriages per thousand unmarried men, and 19.8 marriages per thousand unmarried women in England and Wales.
But older age groups appear to be bucking the overall downward trend: the rates are increasing for men aged 65 and over and women aged 55 and over, according to the Office for National Statistics.
Nicola Haines, of the ONS, said: "The number of marriages between opposite-sex couples decreased by 3.4% in 2015, compared with 2014. Despite this overall decline, marriages at older ages rose."
Harry Benson, research director at the Marriage Foundation, said the record low marriage rates "should give all policymakers deep cause for concern".
Charity Relate noted that research suggests most people see little difference between marriage and living together
He added: "Britain already languishes in shame at the bottom of the developed world league table for family stability, almost entirely due to the trend away from marriage and formal commitment."
Chris Sherwood, chief executive of charity Relate, noted that research suggests most people see little difference between marriage and living together.
"It's not entirely clear why marriage rates among opposite-sex couples are at an all-time low but it could be that the rising cost of marriage is a deterrent," he said.
"It's also possible that many people are now prioritising other things over getting married, such as education, starting a family, buying a house and going travelling.
"This could also be a reason for the rising average age of marriage."
The average age at which people are getting married continues to rise: in 2015 it was 37.5 years for men and 35.1 years for women.