Republic v Mwangi; Equality Now & another (Intended Interested Party); Initiative for Strategic Litigation (ISLA) & 3 others (Intended Amicus Curiae)
The bottom line
#Supreme Court rejects two groups as interested parties but allows experts as friends of the court.
What this practically means
#The Supreme Court of Kenya decided who can join a case about mandatory minimum sentences for sexual offences. Two groups wanted to be 'interested parties' – women's rights organizations and two inmates. The Court said no because they did not show a personal stake in the case or how they would be harmed if left out. However, a group of legal and human rights organizations were allowed to submit expert opinions as 'friends of the court' because they raised new legal points. Each side pays its own costs.
Executive summary
#Questions the Court framed
#The issues the Court set itself to decide, in its own words.
- 1.Whether the 1st joint intended interested parties (Equality Now and CREAW) have met the conditions for admission as interested parties.
- 2.Whether the 2nd joint intended interested parties (Nathan Khaemba Makokha and Hesbon Onyango Nyamweya) have met the conditions for admission as interested parties.
- 3.Whether the joint intended amici curiae (ISLA, KELIN, FIDA, and WLW) have met the conditions for admission as amici curiae.
Key legal issues
#Whether the 1st joint intended interested parties met the conditions for joinder as interested parties.
They did not meet the conditions because they raised issues of public interest generally and failed to show a personal stake or prejudice.
The court applied the principles from Mumo Matemu and Muruatetu, requiring a personal interest or stake, demonstration of prejudice, and submissions that are not a replication of other parties' arguments. The 1st joint intended interested parties sought to address the utility of minimum mandatory sentences generally, which the court found to be public interest issues already addressed by the petitioner, with no personal stake shown.
Whether the 2nd joint intended interested parties met the conditions for joinder as interested parties.
They did not meet the conditions because they failed to show a personal stake in this specific matter or prejudice, and they would add nothing the respondent cannot.
The court noted that while the 2nd joint intended interested parties were in a similar position to the respondent (convicted of sexual offences), they did not demonstrate a personal stake in this specific petition or prejudice from non-joinder. Additionally, one of them had already successfully challenged the mandatory minimum sentences in a separate High Court case, so he could pursue that separately.
Whether the joint intended amici curiae met the conditions for admission as amici curiae.
They met the conditions because they intended to address points of law not already addressed by the parties, including the State's obligation under Article 21(1) of the Constitution and comparative lessons on mandatory minimum sentences.
The court applied rule 19 of the Supreme Court Rules, 2020 and the principles from Mumo Matemu, requiring proven expertise, independence and impartiality, or public interest, and that the brief addresses novel points of law. The joint intended amici curiae proposed to address the State's obligation under Article 21(1) and comparative jurisprudence, which no party had addressed, thus aiding the development of the law.
Legal principles established
#- To be an interested party, you must show a personal, identifiable, and proximate stake in the case, and the prejudice you would suffer if not joined.
- Interested parties' submissions must not merely repeat what other parties will argue.
- To be admitted as amicus curiae, you must prove expertise, independence, impartiality, or public interest.
- An amicus brief must address points of law not already covered by the parties, introducing novel aspects that help develop the law.
- In public interest cases, the court may order each party to bear their own costs.
Court orders
#- 1.The notice of motion dated 21 August 2023 is hereby dismissed.
- 2.The notice of motion dated 24 August 2023 is hereby dismissed.
- 3.The notice of motion dated 23 August 2023 is hereby allowed and the participation of the amici shall be limited to the court's consideration of the amici brief already on record.
- 4.Each party shall bear their costs.
The bench
#One judgment of the whole court — no separate or dissenting opinions.
- Jurisdiction invoked
- Rules 3, 24, 31, and 32 of the Supreme Court Rules, 2020; Article 23(3)(e) of the Constitution
Relief refused
#Joinder of Equality Now and CREAW as interested parties
They raised issues of public interest generally and did not show any personal stake in the matter or prejudice they would suffer if non-joinder.
Joinder of Nathan Khaemba Makokha and Hesbon Onyango Nyamweya as interested parties
They did not show any personal stake in this specific matter or prejudice they would suffer if not joined, and they would add nothing the respondent cannot.
Costs
Each party shall bear their costs.
Quotable passages
#Verbatim from the judgment, each located to the page it appears on in the official PDF — so these can be cited and checked directly.
the 1st joint intended interested parties raise issues of public interest generally and have not shown any personal stake in the matter, nor the prejudice they stand to personally suffer in case of non-joinder
the 2nd joint intended interested parties have not shown any personal stake in this specific matter nor the prejudice they will suffer if not joined as interested parties
the joint intended amici curiae intend to address the court on points of law that no party in the proceedings has addressed including the State's obligation under article 21(1) of the Constitution and comparative lessons on the application of mandatory minimum sentences from other jurisdictions
Key timeline
#Practical implications
#Tightening joinder rules for interested parties
Lawyers advising clients on joining constitutional petitions must ensure the client demonstrates a personal, proximate stake and specific prejudice from non-joinder. Arguments that merely replicate existing parties' submissions will be rejected. For amici, focus on novel legal points—like the State's obligation under Article 21(1) or comparative jurisprudence—to be admitted. This ruling clarifies the strict criteria from Mumo Matemu and Muruatetu.
Limited direct impact on business operations
Businesses dealing with sexual offences (e.g., as employers, service providers, or victims) should note that this ruling is procedural, not substantive. However, the main case challenges mandatory minimum sentences, which could affect sentencing in cases involving businesses. The amici will address the State's duty to develop the law, so businesses should monitor the main petition for potential changes to sentencing that might affect their legal exposure.
How to join a court case as an interested party
If you want to join a case as an interested party, you must show a personal interest or stake in the outcome and specific harm if you are not allowed to join. General public interest is not enough. The court rejected two inmates serving sentences because they did not show a personal stake in this specific petition beyond their own cases. If you have a separate case, pursue it separately rather than trying to join a different matter.
Frequently asked questions
#What is the difference between an interested party and amicus curiae in Kenya?+
An interested party has a direct personal stake in the case and will be affected by the outcome. An amicus curiae (friend of the court) is an expert or public interest body that helps the court by providing arguments on points of law not raised by the parties, without having a personal interest in the case.
Can inmates join a constitutional challenge as interested parties in Kenya?+
Yes, but only if they show a personal stake in the specific case and that they would suffer prejudice if not joined. The Supreme Court rejected two inmates because they did not demonstrate a personal stake in this particular petition beyond their own separate cases, which they could pursue independently.
What are the requirements for joining a Supreme Court case as an interested party in Kenya?+
You must show a personal, identifiable, and proximate interest in the matter, the prejudice you would suffer if not joined, and that your submissions are not merely a replication of what other parties will argue. The court applies the principles from Mumo Matemu and Muruatetu.
Why did the Supreme Court reject Equality Now and CREAW as interested parties in Kenya?+
The court found that they raised issues of public interest generally, such as the utility of mandatory minimum sentences, without showing a personal stake or prejudice from non-joinder. Their arguments were already being addressed by the petitioner, so they did not meet the criteria for interested parties.
Cite this brief
#Cite this brief
Caselaw, "Republic v Mwangi; Equality Now & another (Intended Interested Party); Initiative for Strategic Litigation (ISLA) & 3 others (Intended Amicus Curiae)", Case Analysis (2023). Petition (Application) E018 of 2023. Source: https://new.kenyalaw.orghttps://new.kenyalaw.org/akn/ke/judgment/kesc/2023/99/eng@2023-11-10
Suggested citation format for research notes or client memos. Always verify the original judgment before relying on any point.