It is relatively common to see conduct pleaded by aggrieved litigants in financial remedy proceedings. It is far more unusual for such an argument to actually succeed and an award to be made reflecting such a finding. Section 25(2)(g) of the Matrimonial Causes Act 1973 states that conduct is only relevant “if that conduct is such that it would in the opinion of the court be inequitable to disregard it”. The House of Lords in Miller v Miller; McFarlane v McFarlane  1 FLR 1186, HL made it clear that “in most cases” conduct would not be relevant, and that appears to have been the approach of the courts since.
Where arguments have succeeded, they have generally involved conduct which has had a financial effect on the parties. It has long been established that gambling away the parties’ assets can result in an adjusted award (M v M (Third Party Subpoena: Financial Conduct)  2 FLR 1253, FD). Similarly, a physical assault on a wife, diminishing her earning capacity, was accepted as meeting the section 25(2)(g) test (H v H (Financial Relief: Attempted Murder as Conduct)  1 FLR 990, FD).
Litigation conduct is a well-established ground under the same section, which more usually results in a costs order rather than an adjustment of the award itself. It is, however, of note that where the assets in the case are modest, the making of a costs order can effectively adjust the financial award in any event.
Cases where non-financial conduct arguments have succeeded are harder to come by. The recent case of FRB v. DCA [No. 2]  EWHC 754 (Fam), heard by Mr Justice Cohen, is one such example. The parties were both from exceptionally wealthy families (each party estimated the other family’s worth at over £2 billion). They lived a lavish lifestyle, with estimated annual expenditure of over £10 million.
They separated after 14 years of marriage, at which point the husband heard rumours that the wife had been having an affair during the marriage. He took a paternity test which confirmed that the child of the family, C, (who at separation was aged 8) was not the husband’s child. The wife admitted the affair and gave the identity of C’s father.
The husband claimed that the wife’s conduct was such that it could not be ignored. Meanwhile the wife argued that it had not occurred to her that the child could have been her lover’s. After hearing extensive cross-examination of the wife, Cohen J concluded that “W did not know that she was carrying another man’s child, but it is impossible to believe that the thought that the child was not H’s never crossed her mind… I regard that evidence as incredible”. The judge was clear that the fact and extent of the affair itself did not fall within section 25(2)(g) (and he cited Miller; McFarlane in support of the same) but that the wife’s silence and the effect of it on the husband were “devastating” to the husband, and could not be ignored.
To what extent the financial award should be adjusted to reflect such conduct was a far more difficult issue. As Cohen J pointed out, “there is no guidance in reported authority as to how this sort of conduct should be reflected”. He noted that he could not speculate what would have happened if the husband had been informed of the wife’s unfaithfulness. The judge also stated that the paternal relationship that the husband has with C has been “of enormous value” to both. Although the husband raised in argument the financial burden of raising C, it is not something that the judge chose to address, instead focusing on the emotional impact alone.
Cohen J remarked just how difficult it was to try to put a figure on the emotional damage caused to the husband; he likened doing so to “comparing apples and pears”. In the circumstances (and somewhat unfortunately for all lawyers looking for guidance on how to quantify a successful conduct argument), the judge made no adjustment to the overall award. However, this was because he had already made a finding that the husband had been “seriously deficient” in his disclosure, and the judge was confident that the husband had access to or ownership of further assets which could not be quantified. In those circumstances, he held that no adjustment in the husband’s favour was necessary.