■ Limitations to constitutional amendments: unamendable provisions

Beside the various degrees of procedural limitation stated above, some constitutions also introduced substantive and irrevocable limitations through a clause that sets restrictions to amend parts of the constitution at all.  Such a clause might refer to central pillars of the constitution, to rights given to minorities, to human rights, to religion, to sensitive parts of the constitutional agreement or to issues that historically have caused bitterness and should not be subject to revocation again. However, the decision to make parts of the constitution unamendable should not be taken lightly: Even consensus in parliament backed by strong support from the people might not qualify to alter the content of the pertinent provisions.

The way existing constitutions have phrased such a clause differs widely and might serve as an initial inspiration for what clause –if at all- might be appropriated for a specific country:

• Some constitutional provisions are rather vague, only prohibiting a constitutional amendment that runs counter to its principles and spirit, without clearly identifying them. As a result, it remains nebulous what might be amended or not and might cause more uncertainty than stability.
• Frequently, the clause refers to provisions relating to the structure of the state, human rights, mode of government, etc.
• Sometimes, reference is made to very specific issues such as fixing the terms of the president. Specifically in formerly authoritarian regimes still relying on a strong president in the new constitution, such a clause is used (Honduras, El Salvador, Niger, and Mauritania).  
• Sometimes, limitations to amend the constitution are not focusing on substantive issues, but prevent constitutions to be altered during times of war or emergency.
• Occasionally, a self reference is included to underscore that the spirit of that clause is not circumvented by abrogating the clause as such.