Mario has been involved in the food retail industry for a large part of his life, owning a string of retail outlets in Gibraltar. He read for a degree in law at Southampton Institute of Higher Education (now Solent University) as a mature student. Upon completing his degree he undertook studies in London and the following year he successfully qualified as a Barrister, being called to the Bar of England and Wales at the Middle Temple Inn after which he was admitted to the Bar in Gibraltar. Mario practiced law in the area of commercial litigation and conveyance. In 2003 he was appointed Gibraltar’s second Parliamentary Public Services Ombudsman, a post he held for fifteen years. In his commitment to deliver a first class service to those who required his assistance he developed his office into a centre of excellence in Gibraltar; he stepped down from the post at his own request. Mario is a Consultant to Acquarius Trust assisting the team all legal matters.
In 2019, he was awarded the Gibraltar Medallion of Distinction by the Gibraltar Parliament. Mario is an additional member of the Public Services Commission and a Board member of the Legal Services Regulatory Authority.