The 1970 General Election was won by the Conservative Party, and Heath became Prime Minister. However, the electoral weakness of the Nationalists removed the political pressure for devolution, which caused it to slip from the agenda. The two general elections of 1974 saw the return of a minority Labour Government and advances by the Nationalists (they won 7 seats in the February election and 11 in the October election). Labour was thus dependent on Nationalist support in Parliament, and hence, despite some opposition from within its own party, passed the Scotland Act 1978. This act provided for devolution, subject to approval by a referendum which took place in 1979.