Judgment of the General Court (Fifth Chamber) of 15 September 2021.#Stavros Arnaoutakis and Others v European Parliament.#Law governing the institutions – Rules governing the payment of expenses and allowances to Members of the European Parliament – Amendment of the voluntary additional pension scheme – Refusal to grant a voluntary additional pension – Plea of illegality – Competence of the Bureau of the Parliament – Rights acquired and future entitlements – Proportionality – Equal treatment – Legal certainty.#Cases T-240/20 to T-245/20.