On 13 April 2015, provisions of the Criminal Justice and Courts Act 2015 (the Act) came into force which introduced new rules that are likely to affect the costs exposure faced by third-party interveners in certain proceedings going forward. This briefing sets out the background, introduces the new provisions and suggests some practical pointers for the future.


Under the “old rules” there was a strong presumption that all parties bear their own costs in relation to interventions. Most public interest interveners (usually, charities and statutory bodies) took the view that, with proper conduct, the risk of adverse costs was negligible.

However, it has always been the case that costs could in theory be ordered against an intervener who:

  • behaved unreasonably, or
  • had in effect taken on a role as one of the main parties to the dispute.

A rare example is the case of R (E) v JFS & others where the United Synagogue as intervener became, in effect, one of the main parties.1

For this reason it has always been good practice to seek mutual undertakings from the main parties – agreeing not to seek costs from one another – and to stick carefully to the terms of any order granting permission to intervene.

New provisions

S.87 of the Act effectively puts these two existing categories on a statutory footing and goes further by adding a further two categories, which apply to an intervention which:

  • is not of significant assistance to the court, or
  • relates in significant part to matters which are not necessary for the court to consider.2

If asked by one of the main parties, the court is now under a duty to award costs against an intervener if any of these four criteria are met – unless there are “exceptional circumstances” which make such an order “inappropriate”. This caveat does leave some discretion to the court; however, what will count as “exceptional” or “inappropriate” will turn on the specific facts of the case, and will remain unclear until judicial guidance is available. It could be argued, for example, that it would be “inappropriate” to sanction an intervener whose submissions or evidence – through no fault of the intervener – became academic to the case after permission to intervene is granted.

Practical tips

The new rules only apply:

  • to judicial review proceedings (including appeals from such proceedings) – so the “old rules” continue to apply in other cases and their appeals (for example, possession proceedings, tort claims, asylum claims, human rights claims under s.7 HRA, and – probably – “judicial review” claims brought in the Upper Tribunal);
  • in the High Court and Court of Appeal – so there is no change in the costs position in other forums (including the tribunal system and the Supreme Court); and
  • to judicial review proceedings where the claim form was filed on or after 13 April 2015 – and the new provisions probably only apply to appeals where the underlying judicial review proceedings were commenced on or after 13 April 2015.3

For cases which do fall within the ambit of s.87, the risk of adverse costs can be managed – as under the old rules – by:

  • seeking undertakings from the main parties (but note that there is now less of a reciprocal risk, since s.87(3) rules out costs in favour of an intervener, barring exceptional circumstances);
  • being as clear and full as possible in the application to intervene in setting out the proposed scope of the intervention;
  • sticking assiduously to the scope of any permission to intervene (or asking the court to vary that permission if necessary as the case evolves); and
  • displaying exemplary conduct towards the other parties and towards the court (for example, observing all relevant deadlines and other court rules, ensuring proper service on all parties, etc).

In addition, we recommend that prospective interveners specifically ask the court only to grant permission if it agrees that the intervention as proposed in the application will be of significant assistance and will relate to matters which are necessary for the court to consider.

The future

The new rules do not prevent interventions in judicial review proceedings in the High Court or Court of Appeal. But they do underline the need for careful management of such interventions.

It is essential that you discuss costs with your legal advisers on a case-by-case basis, since s.87 is still untested and we expect both case law and court procedure to develop rapidly.

Note that the Labour Party has stated that if elected to form the next government they intend to reverse this change.4