Japan’s first female prime minister is facing a growing backlash from women new to political activism, as alarm spreads over her government’s push to revise the country’s pacifist constitution and expand its role in arms exports.

The women are part of a protest wave that has grown from a few thousand people in late February to tens of thousands outside the National Diet in Tokyo, where demonstrators have rallied against constitutional revision, weapons exports and what they see as Japan’s drift away from its post-war peace commitments.

For many of them, the issue is not simply whether Japan should update a decades-old charter but whether the country is abandoning the restraints that helped define its place in Asia after World War II.

“I feel anger that Prime Minister [Sanae] Takaichi does not understand that the constitution exists to bind those in power,” Reina Tashiro, a Tokyo business owner involved in the volunteer group We Want Our Future (WWOF), told the Mainichi newspaper.

WWOF has been one of the main groups behind the demonstrations, co-organising the “Emergency Action to Protect the Peace Constitution” rallies with a civic group campaigning against changes to the constitution.