Called to lead the state finances at a time when a great wave of reforms was unfolding, Ormea proved to be a skilled and determined collaborator, capable of interpreting the sovereign's orders and carrying them out with ruthless efficiency.

On 8 August 1730, Victor Amadeus II, who had decided to abdicate, appointed Ormea as the first Secretary of State for the Interior, replacing Pietro Mellarède, who had died on 19 March.

The 'Provisional convention', in particular, was a true diplomatic masterpiece: in it Charles Emmanuel III and Maria Theresa allied themselves against Spain and France, but it was foreseen that, if the former were forced into another alliance, the treaty would lose value, provided that he notified the Queen a month in advance.

Unlike his predecessors, he had not only the insignia of the toga, but also those of the sword: a privilege also due to the choice to maintain the office of Secretary of State for Foreign Affairs (while he gave up that of the Interior).

In the spring of 1742, at the outbreak of the War of the Austrian Succession, Ormea was sent by Charles Emmanuel II to Modena to convince Duke Francis III to side with the Empire.

As evidence of the bond that united them, Charles Emmanuel III wanted d'Ormea to be depicted in the bas-relief of the Battle of Guastalla, which adorns his tomb in the Basilica of Superga.