Campaigning kicked off Wednesday for Japan's upper house elections in July as analysts say Prime Minister Shinzo Abe's ruling camp seeks a referendum to change the country's war-renouncing constitution.
The July 10 elections for the House of Councillors come 10 months after Abe's government pushed through controversial legislation that allows Japanese armed forces to engage in overseas combat for the first time since the end of World War II.
But Article 9 of Japan's charter prohibits the use of force to settle international disputes, and the main opposition Democratic Party and other small parties have tried to garner public support by calling the new law unconstitutional.
Every three years, Japan's upper house has elections for half of its 242 seats. This year a total of 389 candidates are vying for the 121 seats.
Abe's ruling Liberal Democratic Party currently holds a total of 116 seats, and its junior coalition partner Komeito holds 20 seats in the upper house to control the 242-seat chamber, while the Democratic Party holds 63 seats and the Japan Communist Party 11.
The premier would need the support of two-thirds of both chambers of parliament in order to call a national referendum on changing the constitution.
Abe took office in December 2012, vowing to reinvigorate the country's economy and overcome years of deflation. However, his government has failed to achieve long term economic growth.
Japan's economy contracted twice in the past year amid sluggish spending especially after the country's sales tax hike to 8 per cent in April 2014 from 5 per cent.
Household spending fell 2.3 per cent in 2015 for the second straight year of decline, a government report showed.
Abe called economic policy "this election's biggest theme" while campaigning in Kumamoto prefecture, where twin major earthquakes killed 49 people two months ago.
Japan has achieved "the highest wages since the turn of the century," the premier said, adding that he would push his economic policy forward.
But government data contradicts Abe's wage comment: Inflation-adjusted wages were down nearly 4 per cent in 2014, recovering by only 0.1 per cent in 2015, with recent data showing wages falling further.
A poll conducted by Kyodo news agency showed nearly two-thirds of those surveyed - 62.2 per cent - expressed doubts about the effectiveness of Abe's economic policy. Some 28 per cent voiced confidence that the policies will boost the economy.
The yen's recent sharp rise and slow growth in emerging economies, including China, bodes ill for Japan's economy. The appreciation of the currency makes Japanese products less appealing abroad and erodes repatriated revenues.
"Real economic policy means balancing growth with the distribution" of wealth, Democratic Party leader Katsuya Okada said in Kofu, central Japan.
It will be the first national elections in Japan in which 18- and 19-year-olds are able to vote, after an electoral law amendment recently reduced the minimum voting age from 20.