Social Party of National Unity primaries, 4203

The Social Party of National Unity (PSUN) of Istalia organized a series of internal elections on 3–4 April 4203, to select its candidates for president and parliament. The primaries were the first held under a new set of rules, as determined at the 4200 party congress. Under the new rules, the party leader will no longer be up for election in every primary election, but will serve until they either resign or are removed by the party executive; the presidential candidate will still be elected by the total party membership as before. The PSUN candidates for the Chamber of Deputies and the Senate will be elected through by the members of the party's constituency branches; previously, the candidate lists were drawn up by an unelected, central committee. The candidate for Prime Minister of Istalia will be chosen by the PSUN's deputies and senators in the national parliament, totalling 34 at the time of the 4203 primaries.

The party leader, Aezio Durante, was chosen as the party's presidential candidate after defeating two rivals, while Flavio Trudu was selected to head the PSUN parliamentary list, and be its candidate for prime minister. The PSUN also nominated 503 candidates for the Chamber of Deputies and 70 candidates for the Senate.