The Nikkei 225 Stock Average closed down 1.57% to 17,099.40 at 2:55 p.m. in Tokyo, while the Topix Tokyo Stock Exchange Price Index had fallen 1.10% to 1384.20 as of 11:55 a.m.
Prime Minister Abe was re-elected on Sunday in a landslide victory for his ruling bloc, which won a majority of more than two-thirds in Japan's lower house of parliament, the Diet. Abe's Liberal Democratic Party and its coalition partner, Komeito, took 326 out of 475 parliamentary seats. The snap election was billed as a referendum on Abe's ambitious economic reform program, which has been nicknamed "Abenomics." However, Monday's market slide reflects doubts about prospects for a fast recovery from Japan's ongoing recession.
Stocks were also down elsewhere in Asia, following declines seen on Wall Street on Friday, after continued falls in oil prices added to concerns about global growth. "The oil price collapse is symptomatic of a lack of global demand,” an expert from RMG Wealth Management LLP, a London investment manager, told Bloomberg. According to the news agency, the MSCI Asia Pacific Index had lost 1% by 1:20 p.m. in Tokyo, reflecting a decline of the key regional stock index to its lowest level in 10 months.