The figures showed that the trend away from marriage was largely confined to low income groups prior to the 1990s but is now spreading to families on middle incomes.
It was found that almost 90% of mothers who had a joint income of more than £45,000 were married compared to one in four of woman with incomes less than £14,000.
The Venerable John Barton who previously worked with the Church of England on marriage told Premier's News Hour spending £20,000 on a wedding was "completely unnecessary".
"I don't want to spoil people's fun," he said, "but you don't have to have a stag night in Prague and a hen night in Majorca, it's completely unnecessary".
"You don't have to have a lavish reception," he added.
He said it was "fashion" that people felt they had to spend up to £20,000.
"You don't have to do it chums," he said.
"The cost of being married in church is just over £450 and you're just as married if you do it economically."
Harry Benson, Research Director for Marriage Foundation, said: "Our research shows a concerning spread in the collapse of marriage among the lowest earners to middle earners over the past fifteen years.
"While our previous report, showed that marriage faces extinction among low earners, today's study shows that the middle classes are fast on course to follow them.
"When a social-economic group turns away from marriage, we see a corresponding hike in the rates of family breakdown.
"It's very easy to understand why. Staying in a relationship over the course of a child's life can be extremely testing at times and takes a big commitment on both sides from the outset.
"While there are cohabiting couples who discuss their future, make the commitment and succeed in staying together, they are unfortunately rare.
"Cohabiting couples make up only 19 per cent of parents but half of all family breakdown."
Sir Paul Coleridge, Chairman and founder of Marriage Foundation said: "It is not only sad but also very concerning that not one but two of the largest sections of society are increasingly turning away from marriage.
"And it is the children who are the main casualties. The single most important factor in a child's development is the stable relationship of the parents and the fact is that long term stability is almost entirely confined to married couples."
