The Estonian National Independence Party (Estonian: Eesti Rahvusliku Sõltumatuse Partei), commonly abbreviated ERSP, was a nationalist political party founded in 1988 in what was then the Estonian SSR. It was arguably one of the first non-communist political parties in the Soviet Union. The National Independence Party represented the radical wing of the Estonian independence movement and used hardline anti-communist rhetoric, in contrast with the Popular Front that cooperated with pro-reform communists. The party gained a majority during the February 1990 elections of the Congress of Estonia. After Estonia regained independence, the ERSP was part of the centre-right government from 1992–1995 and later merged with Pro Patria to form the Pro Patria Union, a national-conservative party.