On the eve of a historic decision, thousands of people turned up at the prime minister's office on Monday evening to shout their opposition to his plan to reinterpret Article 9 of the Constitution to permit collective self-defense, which could pave the way for Japan to wage war.

Prime Minister Shinzo Abe's Cabinet approved a reinterpretation of the pacifist charter at an extraordinary meeting Tuesday, allowing Japan to come to the aid of an ally under attack even when Japan itself is not.

"We will never recognize such a move," said Ken Takada, who helped organize the rally near Abe's office in Chiyoda Ward.

"We must be aware that we're at a historical turning point in post-war Japan," he emphasized. "We will continue to fight at any cost to stop the Cabinet approval tomorrow."

Chanting "Don't destroy the Constitution," "We absolutely oppose reinterpretation of the Constitution," and "We don't need the right to collective self-defense," the protesters carried a wide array of signs, lights and banners to get their message across to the conservative leader.

At one point, a group of apparent right-wing supporters showed up in a speaker truck to interfere with the protest but were shooed away by the police.

Estimates of the size of the rally ranged from 10,000 to 40,000 people.

"I'd like to make the public to know that there are people who are opposing" Abe's drive to reinterpret the war-renouncing Constitution, said Takuya Shigeta, a 53-year-old resident of Fuchu, western Tokyo.

Kinue Yoshino, a 30-year-old employee from Kawasaki, said she joined the rally because she doesn't want to see Japan take part in a war.

A woman in her 50s from Saitama who declined to be named agreed with Yoshino and said she took part to help stop that from happening.

Information from Kyodo added