By Jon Silverman
Legal affairs analyst
Two divorce cases to be decided by the Law Lords raise different issues about sharing the spoils of a failed marriage and both will be studied with great interest.
Melissa Miller was awarded £5m
One significant point is whether the behaviour of one party to a divorce should affect the size of the settlement.
Many family lawyers believe that if the Law Lords rule that it should - in the case of Alan and Melissa Miller - it would revive arguments about fault and blame which have largely been removed from divorce negotiations.
There are two points to be determined in the Miller case.
Melissa Miller was married for less than three years when the couple split up and was awarded a £5m pay-off plus other benefits.
There were no children. One key issue, according to family lawyer Debbie Chism, is whether a wife who gives up earning capacity when she gets married to a wealthy partner, expecting to be financially secure, should receive a substantial sum for blighted expectations.
Judges exercise considerable discretion in adjudicating on the basis of need
"If that is the outcome, then courts will start rummaging through the attic of a marriage to look at what expectations the two sides had on entering the marriage," she said.
In England and Wales, the guiding principle of contested divorce settlements is that there should be a 50/50 split in finances unless there are compelling reasons to do otherwise.
This was laid down by the Law Lords in the landmark case of White v White in 2000.
The Whites had built up a £4.6m farming business in Somerset during 33 years of marriage. But Pamela White had been given just £800,000 when she and her husband divorced in 1995.
She wanted a more equal share of the business, and following a ruling by the Court of Appeal in June 1998 received a further £700,000.
Nevertheless, judges exercise considerable discretion in adjudicating on the basis of need.
In Scotland, by contrast, maintenance is available for a maximum period of three years and the courts disregard assets which were not built up during the marriage.
Some English family lawyers, who argue that the balance has shifted too far in the favour of women in high-income divorces, think the Scottish model is a good one and could be the basis for much-needed reform.
The other key question in the Miller case is whether the size of the settlement should be affected by Alan Miller's infidelity.
The Court of Appeal took this into account when turning down his appeal against the £5m award. But it was a decision which went against two decades of case law.
It remains an open question as to whether the Law Lords rulings will have a bearing on Paul McCartney and Heather Mills
In the second case to be decided by the Law Lords, Julia McFarlane is appealing against a ruling that her divorce settlement of £250,000-a-year should be restricted to a five-year period.
She argues that she gave up a high-earning career when she married her husband, Kenneth, 18 years earlier, and that her payment should last for life.
The outcome of this case has implications for anyone whose assets are insufficient to fund a clean break when they divorce.
It remains an open question as to whether the Law Lords rulings will have a bearing on Paul McCartney and Heather Mills.
But there will almost certainly be a fresh impetus for reform of the divorce law which has remained largely unchanged since 1969.