Setting aside findings of alienating behaviour and the role of unregistered experts following Re Y (Experts and Alienating Behaviour: The Modern Approach) [2026] EWFC 38

In Re Y the President of the Family Division Sir Andrew McFarlane provides clear guidance on the modern approach to be adopted when faced with allegations of alienating behaviour. The President also sets out the appropriate route for parties to take when seeking to set aside findings of parental alienation.

Background

In December 2014, the mother and father separated and subsequently divorced. In 2018, an order was sought by the father for the two children to move and live with him. Allegations of domestic abuse were made by both parents against one another. 

In April 2019, the children’s guardian made an application for Ms Melanie Gill to undertake a “specialist family assessment” as a single joint expert. However, as Sir Andrew McFarlane Pmade clear, “Ms Gill does not have a clinical or therapeutic practice in which she sees patients. Whilst her CV lists membership of a range of organisations, Ms Gill is neither a chartered psychologist, nor registered with the Health and Care Professions Council [‘HCPC’].” ([9]). The report of Ms Gill was received in September 2019 at the conclusion of which she found ‘extensive evidence’ that the children were suffering from active alienation by their mother, and as a result the children should be removed from their ‘traumatising environment and relationship with their mother’. The Guardian concurred with the recommendation of Ms Gill.

At a hearing in October 2019, the court heard oral evidence from Ms Gill and no other witnesses. The judge determined at the conclusion of her evidence that the children had suffered from alienating behaviour of their mother towards their father. No other evidence from any other witnesses was heard. At the end of October, the mother launched an application for permission to appeal

In December 2019, with the above application having not been determined, an order was made for the two children to move and live with their father. X, the eldest, was 12, and Y was 9 years old. The children had no contact with their mother between the end of 2019 until 2025.

In early 2025, X had moved to live with her mother for a couple of months before returning to the father. In November 2025, Y, who was then 15 years old, left the father’s home, moving to live with his mother. However, Y was removed into police protection, spending a period of time in foster care until an order was made for him to stay with a friend of the mother.

The Part 18 Application

In April 2025, the mother applied under the Family Procedure Rules 2010 Part 18 to reopen and set aside the findings made in light of new material, namely the decision in Re C (‘Parental Alienation’; Instruction of Expert) [2023] EWHC 345, and the guidance on alienating behaviours issued by the Family Justice Council in December 2024.

The Court began by setting out the required three-stage approach in determining such applications set out in Re CTD (A Child) (Rehearing) [2020] EWCA Civ 1316. The present application concerned only the first stage, namely ‘(1) The court asks first whether the applicant has shown that there are solid grounds for believing that the previous findings require revisiting’.

The Court then conducted an evaluation of recent guidance and authorities on (1) instruction of expert psychologists and (2) the modern approach to parental alienation.

Instruction of experts

The President provided helpful and clear guidance on the instruction of expert psychological witnesses in light of the significant concerns surrounding the use of unregistered experts, setting out that “[i]n future, permission should not be given under CFA 2014, s.13 for the instruction of an expert ‘‘psychologist’ who is neither registered by a relevant statutory body, nor chartered by the BPS. It would be good practice, before a potential expert is appointed, for them to be asked to state whether they hold an HCPC protected title, and if so what that is, before any order is made appointing them as an expert. The ‘registered or chartered’ requirement should only be departed from where there are clear reasons for doing so (for example no registered or chartered expert is reasonably available); where that is so, those reasons should be set out in a short judgment” ([73]).

The President warned against the stark impact if findings are made, such that it “may lead to a radical dislocation of family relationships that is sustained over a period of years” ([74]). It is integral therefore that a “degree of rigour” is applied both by professionals and the court when considering the instruction of an expert (ibid). This applies both in public law and private law proceedings.

Alienating behaviours

It is important to note from the outset that “[t]he factual matrix around allegations of alienating behaviour is a matter for the court alone” and “[a]ny findings of fact once made will then, but only then, be important material for an expert or CAFCASS officer tasked with advising the court on issues of welfare” ([45]).

The Court clarified the modern approach to the question of alienating behaviours at paragraph [75] which, by way of summary, is as follows:

i) the reason for the court’s investigation should be ‘a child’s unexplained reluctance, resistance or refusal to spend time with a parent’, rather than the allegations that one or other parent may be making against the other;

ii) Where a child is reluctant, resisting or refusing to engage in a relationship with a parent or carer (element one), then the court’s focus will move to element two to consider whether that reluctance, resistance or refusal is a consequence of the action of the estranged parent, where it is alleged that that parent has been abusive to the child and/or caring parent;

iii) If it is found that the estranged parent has not behaved in a way in which the child’s reaction can be seen as an ‘appropriate justified reaction’, or, for other reasons, it is found that the child’s reaction is not caused by any factor such as a child’s ordinary alignment, affinity or attachment to the parent with care, then the court willmove on to element three;

iv) At the stage of element three the court will focus on whether the caring parent has engaged in alienating behaviours that have directly or indirectly impacted on the child, leading to the child’s reluctance, resistance or refusal to engage with the estranged parent.

v) Where domestic abuse is alleged, and there is a cross-allegation of alienating behaviour, if a fact-finding process is required, the focus of the fact-finding must be to 

(1) determine the issues of domestic abuse and 

(2) to consider whether the child’s refusal to engage with the estranged parent is an ‘appropriate justified reaction’ to any abusive behaviour, or that what has occurred is the result of protective behaviour or a traumatic response on the part of the victim parent.

vi) Courts should not determine the issue of alienating behaviour on its own without determining the underlying facts and, where it is alleged, the primary issue of domestic abuse;

vii) Courts should not appoint an expert to advise in cases where a child is reluctant, resistant or refusing to engage with a parent unless and until there is clarity and, if necessary, facts that have been found, as to the parents’ past behaviour towards each other and the child and, if domestic abuse is proved, whether the child’s reaction to that behaviour is an appropriate one.

Determination of the Part 18 Application

The mother was successful in her application given that “the judge in the present case fell into a basic error by not establishing the factual matrix first, in particular whether there had been domestic abuse … before considering any expert evaluation” ([82]). The judge, without making his own factual determination, had accepted Ms Gill’s analysis. The following faults in the approach to case management and in making the findings of fact were identified:

i) Where there were serious cross-allegations of domestic abuse, the question of whether to instruct an expert psychologist or file a final s.7 report ought to have been postponed until after any fact-finding process

ii) An unregistered psychologist “should not have been instructed to provide a psychological assessment at any stage of Family Court proceedings relating to children” ([83])

iii) Given that Ms Gill had no clinical practice, it was concerning that the proposal to instruct Ms Gill had been endorsed by the court

iv) A fact-finding should have been conducted to contextualise the allegations put forward by the mother  

v) The court should not have directed the filing of final reports by the expert and Guardian before a fact-finding hearing

vi) There was a “fundamental error” in hearing Ms Gill’s evidence first, and not hearing any other evidence before accepting Ms Gill’s analysis and conclusions ([83])

It was made clear however that the substance of the grounds which the mother was seeking to rely on were not necessarily ‘new’. Whilst there had been further guidance both by the Courts and the Family Justice Council in 2023 and 2024, “[m]uch of what is contained in the ‘new’ material was known of, or was part of developing good practice over the preceding period” ([80]). What had changed was that such practice had been set out in a more concise and clear format in the published guidance.

Appeal or Part 18?

The Court also addressed the additional matter of whether an application for permission to appeal would be more appropriate in these circumstances. It was determined that the more appropriate route is in fact an application under Part 18 given that: (1) there is no need to apply for an extension of time; (2) an appeal is “something of a blunt instrument” as the appeal can only be allowed or dismissed; and (3) if the appeal fails a second appeal “faces a higher permission threshold” ([76]).

Practical Takeaways

• Where there are unresolved allegations or cross-allegations of domestic abuse, it is for the court to determine the facts – expert opinion is not a substitute for judicial determination

• Unregulated experts should not be instructed except where clear and substantive reasons are provided for such an instruction 

• When dealing with allegations of parental alienation, utilise the structured approach set out by Sir Andrew McFarlane P and refer to the Family Justice Council Guidance both on the instruction of psychologists as expert witnesses in the family courts and on allegations of parental alienation

• Part 18 is the appropriate route to take when seeking to set aside findings of parental alienation – this is so even when such findings may have been made prior to the FJC Guidance, as was the case here