The Estonian National Independence Party (Estonian: Eesti Rahvusliku Sõltumatuse Partei), commonly abbreviated ERSP, was a nationalist political party founded on 20 August 1988 in what was then the Estonian SSR. Founders of the party were nationalist and anti-Communist dissidents. The initiative to establish Estonian National Independence Party came from Vello Väärtnõu, the leader of an Estonian Buddhist Brotherhood group. On 30 January 1988 he organized a press conference in Moscow for Western media where he announced the formation of ENIP, aimed at re-establishing independence of the Estonian Republic as a nation state on the restitution principle. This made the ENIP the most radical or political movement of its day. Vaartnou and fellow Buddhists were expelled from the Soviet Union shortly after the press conference and ENIP was officially founded in August 1988 in Pilistvere.(Simons, Westerlund "Religion, Politics and Nation-Building in Post-Communist Countries"
It was the first non-communist political party 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.