A woman who wants to divorce her husband of 40 years because she says their marriage is unhappy has lost her case.

Judges “reluctantly” told her she must remain his wife, because an unhappy marriage is not adequate grounds for a divorce if one spouse refuses to agree.

Five judges at the UK’s highest court unanimously upheld rulings by a family court and the court of appeal that Tini Owens, 68, must stay married to Hugh Owens, 80, despite her complaint that the marriage is loveless and has broken down.

“The appeal of Mrs Owens must be dismissed. She must remain married to Mr Owens for the time being,” supreme court judge Lord Wilson said in the majority judgment. But, he added: “Parliament may wish to consider whether to replace a law which denies to Mrs Owens any present entitlement to a divorce in the above circumstances.”

Tini’s case has thrust the country’s lack of provision for no-fault divorce into the spotlight. Even spouses mutually seeking to end a marriage must, unless they have been living apart, assign blame and make often-damaging allegations, which lawyers say can turn potentially amicable proceedings inflammatory.

Tini and Hugh were married in 1978, lived together in Broadway, Worcestershire, and have two grown-up children. Tini first consulted solicitors about a divorce in 2012. However, despite her engaging in an affair, they remained living together until February 2015.

In May of that year, Tini petitioned for divorce, alleging that her husband had prioritised his work over their home life, that his treatment of her lacked love and affection, that he had often been moody and argumentative, that he had disparaged her in front of others, and that she had grown apart from him.

The supreme court justices analysed the rival legal arguments, which revolved around concepts of “unreasonable” behaviour and “fault”, at a hearing in London in May. They delivered their ruling on Wednesday.

Lord Wilson noted in the judgment that Tini would be able to divorce in 2020, when the couple will have been separated for five years.

In a concurring judgment, his colleague Lady Hale said she found it “a very troubling case”, but that it was not for judges to change the law.

Barring a change of heart by Hugh, Tini must remain married to him until at least 2020, by which time she will be eligible for a divorce without consent or evidence of fault.

Resolution, the organisation that represents 6,500 lawyers working in family law and supports the introduction of no-fault divorce, said the judgment confirms there is a “divorce crisis” in England and Wales.

While it is rare for spouses to defend a petition for a divorce, legislation makes it difficult for even mutual divorces where, in the absence of a period living apart, one party must provide evidence of unreasonable behaviour or adultery before the marriage can be ended.

Nigel Shepherd, the body’s former chair and long-time campaigner for no-fault divorce, said: “Resolution intervened on behalf of Mrs Owens because we believed that under the current law there should be a way to free her from a marriage that is clearly over.

“In practice, our current laws can often create unnecessary conflict in divorce – forcing couples to blame each other when there is no real need, other than a legal requirement, to do so. For over 30 years, Resolution has been campaigning for a system fit for a modern age, where separating couples are treated like responsible adults and supported to resolve their differences as amicably as possible.”

Simon Fisher, a divorce lawyer at solicitors Gardner Leader, said it was likely that divorce petitions would likely become more extreme. “It’s extremely likely that we’ll see a rise in divorce petitions containing embellished and inflammatory grounds for divorce to ensure that applications proceed without any issues as in the Owens’ case,” he said.