When a marriage ends, both parties might feel that the other has behaved unreasonably and that this has caused the relationship to break down. The law recognises the impact of such “unreasonable behaviour” through s 1(2) of the Matrimonial Causes Act, which provides that the court can grant a divorce on the basis that one party has behaved in such a way that the other cannot be reasonably expected to live with them. This is commonly known as “unreasonable behaviour.” What constitutes “unreasonable behaviour” in the context of divorce?

There are some obvious examples of “unreasonable behaviour” which will be accepted by the courts in a divorce petition. These include physical violence, verbal abuse, cruelty and intimate relationships with other people even where no adultery has been committed. The picture becomes more complex where the behaviour is not so extreme. “Unreasonable behaviour” is a subjective concept that can mean different things to different people. What is reasonable to one person may be wholly intolerable to another.  However, in Bannister v Bannister (1980) (10 Fam Law 240, CA), it was held that the test for “unreasonable behaviour” is not whether the Respondent’s behaviour is unreasonable in itself, but whether the effect of it is such that the Petitioner cannot reasonably be expected to continue living with them. This means that lack of affection, not contributing to household chores, frivolous spending, differences in religious or political belief, working long hours or refusing to work can all qualify as “unreasonable behaviour” for the purposes of a divorce petition, as long as the Petitioner finds such behaviour genuinely intolerable to the extent that it has caused the marriage to break down.

Where clients wish to divorce as amicably as possible but would prefer not to wait until they have been separated for 2 years and no adultery has been committed the notion of relying on “unreasonable behaviour” is understandably not very appealing. However, it is important to note that the contents of a divorce petition remain private and have no impact upon any related financial proceedings. Also, there exist mechanisms designed to minimise animosity where “unreasonable behaviour” is relied upon. As set out above, the stated behaviour allegations can be very low key and parties are encouraged to agree the contents of the Petition before it is sent to court, in accordance with the Resolution Code of Practice.