Thousands of demonstrators, many of them elderly, congregated in Tokyo, demanding the resignation of Prime Minister Shinzo Abe. They also called for a contentious law allowing the military to fight abroad to be overturned.

The protestors were making their demands ahead of an election for parliament's upper house on 10 July, according to Reuters. In a largely peaceful rally in front of Japan's parliament building, the demonstrators held placards saying "Step down, Abe government" and "Citizens change politics".

The Sunday rally organisers said around 40,000 attended and there were reports of right-wing activists attempting to reach the demonstrators, although they were stopped by police.

Abe "is trying to highlight as an election issue Abenomics, which has already failed" Aki Okuda, from the Students Emergency Action for Liberal Democracy said. "But his real intention seems that he wants to take a two-thirds majority (in the Upper House as well) in order to revise the constitution," he told Jiji Press.

In the upcoming election, opposition parties are fighting to keep Abe's ruling coalition from winning the majority of the 121 seats up for grabs in the 242-member chamber, where it has an overall majority. Abe's Liberal Democratic Party and its junior coalition partner, Komeito, form the ruling bloc.

Democratic Party leader Katsuya Okada suggested that if Abe attained a two-thirds majority, the PM would be in a position to amend the constitution for the first time. "This is what we must prevent at all costs," Okada said.

This would pave the way for revising the pacificism of Article 9 of Japan's constitution which states: "The Japanese people forever renounce war and the threat or use of force."

Abe's approval rating increased to 56% after he hosted a G7 Summit in May and escorted President Barack Obama on a visit to Hiroshima, a Nikkei business daily survey showed. However, the Japanese president refused to say whether he would step down if the ruling parties did not win a majority of seats in the Upper House election.

"We will win at the polls and, by all means, the ruling bloc will secure a majority of the seats at stake. I'm obsessed with that," Abe said in a Japan Times report.