NEW DELHI – Hundreds of supporters of India’s youth-led “cockroach” movement gathered in the capital New Delhi on July 20 to march on parliament, seeking the resignation of the education minister despite police denying permission for the protest.

The months-old movement and the planned protest is seen as the biggest public challenge to Prime Minister Narendra Modi in his third term in office, garnering millions of supporters on social media and mobilising support on ground.

The movement has been galvanised since police forcibly moved hunger-striking ...