Lovers have little interest in prenuptial agreements, according to research by lawyers.
Nearly four in 10 people questioned in a survey said entering into a "prenup" had never crossed their minds.
More than four in 10 said they were "happy to keep to the traditional marriage system".
London law firm Seddons and the Marriage Foundation, a charity which aims to promote "stable relationships", commissioned the survey and research consultancy Populus questioned more than 2,000 adults.
A Seddons' spokeswoman said results showed a "staggeringly low level of interest" in "prenups".
"Just 2% of the married respondents had entered into a prenup before getting married, with the vast majority (95%) never even discussing a prenup as an option," said the spokeswoman.
"Of those respondents that are living with a partner, but not married or in a civil partnership, only 4% had in place a cohabitation agreement, with 79% of cohabiting respondents stating they were not even aware of the existence of cohabitation agreements."
She added: "Despite the cost of divorce being high, almost half (45%) of respondents cited 'being happy to keep to the traditional marriage system' as the main reason for not getting a prenup. Almost four in 10 respondents (38%) said entering a prenup had never crossed their minds."
Lawyer Deborah Jeff, head of the family department at Seddons, said: "Despite the increasing public references to prenuptial agreements, particularly amongst high-net worth individuals, our research has found that for the vast majority of people prenups are not a part of their relationship planning.
"There is a lack of understanding of how important a prenuptial agreement may be and its enforceability now in English law.
"Provided the agreement is properly prepared, fair and all reasonable needs are met, they can be of magnetic importance and extremely persuasive if a marriage ends in divorce.
"They also demonstrate to a court that from the outset of a marriage the parties had decided for themselves how their finances should be divided."