[4] Arias supported the Ernesto de la Guardia administration in 1956-1960 and served as Minister of Finance and Treasury (1957–1958).
[5] Aquilino Boyd led the agitation against the Canal Zone [6] , and delivered the TPN to the National Liberal Party (PLN) coalition in on the basis of Roberto Francisco Chiari Remón's nationalist stance.
Shortly after the 1960 election Aquilino Boyd lost control of the TPN to Gilberto Arias Guardia.
[7] Boyd withdrew his faction and created the Nationalist Party (PN), which joined the PLN coalition (1964).
Gilberto Arias returned the TPN to the CPN coalition for, and is supporting Juan de Arco Galindo (1964).