Contribution key. 1. The contribution key for subscribing to ESM authorised capital stock shall, subject to paragraphs 2 and 3, be based on the key for subscription, by the national central banks of ESM Members, of the ECB's capital pursuant to Article 29 of Protocol (No 4) on the Statute of the European System of Central Banks and of the European Central Bank (the "ESCB Statute") annexed to the Treaty on European Union and to the TFEU.