In 1947, Frey joined the anti-communist Rassemblement du Peuple Français (RPF) (Rally of the French People) and was a member of the steering committee of the Gaullist movement, in 1951 he became the Treasurer.

A close colleague of Jacques Soustelle he was active during the crisis of May 1958, preparing for the return of Charles de Gaulle to power.

Under President Georges Pompidou he served as the Minister of State for Relations with the Parliament of 6 April 1967 to 31 May 1968.

In 1964, he enforced the prosecution of the use of monokini, a women's one-piece bathing suit that leaves the breasts uncovered.

Such bathing suit, Mr. Frey went on to say, "constituted a public offense against the sense of decency, punishable according to article 330 of the penal code.