A woman who lived with her partner for nearly two decades is to find out the result of a court battle she launched after his share of their home passed to his estranged wife after his death.
Lawyers for 69-year-old grandmother Joy Williams say the case highlights the need for the law relating to cohabitation to be reformed.
Ms Williams lived with dentist Norman Martin for 18 years, but he remained married to wife Maureen Martin.
Mr Martin died of a heart attack in 2012 and his share of the house and assets passed to his wife.
Law firm Irwin Mitchell say Mr Martin did not divorce or update his will to "reflect his relationship with Ms Williams".
They owned their three-bedroom home in Dorchester, Dorset, as tenants in common, which meant the house did not automatically pass to Ms Williams after her partner's death.
A judge at the Central London County Court is to rule on the dispute on Tuesday.
He has been being urged to award Mr Martin's share in the home to Ms Williams "so that she has some security for the future".
Paula Myers, national head of contentious trusts and probate department at Irwin Mitchell, said: "This case highlights the needs for cohabitation laws to be brought into the 21st century.
"Too many people do not realise the risks of cohabiting without putting their legal and financial affairs in order.
"Couples who cohabit do not have the same rights as married couples or those in a civil partnership. The idea of a common-law husband or wife is an urban myth.
"Couples considering moving in together without getting married should set up a cohabitation agreement. This is a legally binding document that outlines who owns property, how household bills are divided and maintenance payments for children.
"Couples should also ensure their wills are up to date. If the wills in this case had been updated, the case would not have needed to come to court."