Unmarried couples: the new law of the ex

Divorce is no longer just for married couples: in the future, under new proposals put forward by the Law Commission, those who live together may also be able to make financial claims against their former partners.

The plans, announced last week, would apply only to those cohabiting couples who have children or who have been living together for an extended period – likely to be set at between two and five years.

While the Conservatives and Christian groups have condemned the proposals as encouraging "marriage lite", lawyers say they would provide just the minimum of protection. Ann Thomas of solicitors Boodle Hatfield says cohabiting couples would not be expected to make ongoing maintenance payments except for the cost of childcare, and that there would be no guiding principle – as there is in divorce – that assets should be split equally.

"What these recommendations will do is offer [some] protection to a group of people who are very vulnerable," she adds.

Claire Blakemore, from the family division at Withers solicitors, says: "They will ensure greater justice and fairness for a large section of the population."

There were two million cohabiting couples in the UK in 2003, and this figure has risen to an estimated 2.2 million today, according to the Government Actuaries Department. "By 2031, the number of people living in unmarried relationships could represent almost a third of all partnerships," says David Kuo, from the price-comparison website Fool.co.uk.

The Law Commission says the enactment of these proposals would lay to rest two misconceptions. The first is the "common law" myth, which holds that unmarried couples will be treated by the law as though they are married – so long as they have been together for a considerable period.

The second is the idea that cohabitants are ignored by the law altogether. Once again, this is not the case, but the current patchwork of legal rules amounts to a system described by the Law Commission as "uncertain, expensive to rely on and often giving rise to outcomes that are unjust".

Under the new plans for cohabitees, you would need to satisfy three tests to make a claim against your former partner. First, the relationship would have to be eligible, in terms of children and the length of time spent living together.

Second, the claimant would need to demonstrate that he or she had made "qualifying contributions" to the relationship. These might be financial, but they could also include caring for children, say, or unpaid work for the partner.

Third, the claimant would need to show that he or she had contributed to their partner's "retained benefit", such as helping to pay a mortgage during a time of property price rises, or had a continuing economic disadvantage as a result of contributions to the relationship. For example, income might have been lost as a result of staying at home to look after children.

Any claim against an ex- partner would need to be made within two years of the relationship failing.