Family lawyers predict a rise in the number of couples seeking prenuptial agreements after the Court of Appeal dismissed a woman's bid for an equal share of her and her ex-husband's assets.

Ruling in Hart v Hart, Lord Justice Moylan, said His Honour Judge Wildblood QC did not err when he awarded Karen Hart £3.5m, out of total resources of just under £9.4m, in a financial remedy order made in June 2015.

The couple were married for 23 years. Karen Hart's solicitor, Irwin Mitchell partner Nicola Walker, said the settlement 'should have been based on an equal sharing of the assets they created between them during this time'.

Walker said yesterday's ruling 'leaves the law in a state of flux. It allows a trial judge to find that even where it is not properly evidenced, the financial contribution of one spouse outweighs the family and domestic contribution of the other. This can lead to a result that is unfair and discriminatory, as it has done in this case. More such results are likely to follow, with the potential to set the law back more than 20 years'.

Joanna Farrands, partner at Surrey firm Barlow Robbins, said it was unusual for so much weight to be given to pre-marriage contributions after such a long marriage.

'For others, this means that it's important than ever to establish and prove what assets you have invested into the relationship prior to the official marriage as they could also be included in any payout. We could potentially start to see a rise in prenuptial agreements by couples as a result,' she said.

Simon McKirgan, senior director at family law firm Vardags, said the courts draw a clear distinction between wealth built up during the course of the partnership and that generated by one party prior to the marriage.

He said: 'If such wealth exists, as it clearly did in the case at hand, then the party that brought this wealth to the marriage will, in most circumstances, be entitled to retain it. However, this is subject to one important caveat. If there are not enough assets to meet the financially weaker party's needs, then the court will award them a portion of the other side's pre-acquired wealth to ensure that those needs are met. Needs are always regarded as more important than protecting pre-acquired wealth and, in such a scenario, trump all else.'