Claim: Prime Minister Kalevi Sorsa, of the Social Democratic Party, served in office from 6 May 1983 – 30 April 1987.
Evidence: The third cabinet of Kalevi Sorsa was the 62nd government of Finland. The majority government lasted from 19 February 1982 to 6 May 1983. The cabinet's prime minister was Kalevi Sorsa. Sorsa's fourth cabinet was the 63rd government of Finland, which existed for 1 456 days, from 6 May 1983 to 30 April 1987. The government's Prime Minister was Kalevi Sorsa. 
Prime Minister Kalevi Sorsa 19 February 1982 6 May 1983 6 May 1983 – 30 April 1987 Prime Minister
Kalevi Sorsa Social Democratic Party