The NPS emerged from the consensus among members of these groups, and the Scottish Home Rule Association, that an independent political party, free of any connections to any existing parties, was the best way forward for achieving Scottish Home Rule.
The NPS contested the 1929 and 1931 United Kingdom general elections, and a number of by-elections.
The NPS was formed in 1928 after John MacCormick of the Glasgow University Scottish Nationalist Association called a meeting of all those favouring the establishment of a party favouring Scottish Home Rule.
The poet Hugh MacDiarmid was a member, but was expelled on account of his communist views (ironically, he would later be expelled from the Communist Party of Great Britain for his Scottish Nationalist beliefs).
He contested Midlothian and Peebles Northern at a by-election in 1929 and came fourth, with 4.5% of the vote.