Chairman of the Finnish Social Democratic Party Antti Rinne and his wife Heta Ravolainen-Rinnes attend the election party in Helsinki, Finland April 14, 2019. Lehtikuva/Antti Aimo-Koivisto via REUTERS

HELSINKI (Reuters) - Finland’s leftist Social Democrat party (SDP) leader Antti Rinne has declared victory in Sunday’s general election, after partial results showed his party winning by a tight margin with 17.8 percent.

The nationalist Finns Party was in second place with 17.6 percent, after more than 97 percent of votes were counted.

“For the first time since 1999 we are the largest party in Finland ... SDP is the prime minister party,” Rinne said.