Since the Parliament of South Africa committed itself to a policy of expropriation without compensation (EWC) in February 2018, Martin has written widely on the so-called basic structure doctrine of constitutionalism. According to this doctrine, while a legislature usually does and may have the power to amend a constitution, it does not have the power to destroy it by changing its nature, logic, or foundational principles — its basic structure. Martin has argued widely in the academia and popular media that amending the Constitution of South Africa to provide for EWC might amount to a breach of the Constitution’s basic structure, and is therefore outside of the power of Parliament.
In October 2018, Martin did a presentation to the Libertarian Society of South Africa on the basic structure doctrine as applied to EWC. In February 2019, the peer-reviewed attorneys’ journal, De Rebus, published a centrepiece article, “The basic structure doctrine: A challenge to expropriation without compensation?”, authored by Martin on the basic structure doctrine. This was followed in October 2020 by a longer paper, “Property rights and the basic structure of the Constitution: The case of the Constitution Eighteenth Amendment Bill”, published in the peer-reviewed Pretoria Student Law Review.