Hundreds of thousands took to Hong Kong streets on Sunday, defying military threats from Beijing and torrential rain in efforts to reset the tone of a political movement that has embroiled the city all summer.

Demonstrators, including infants and the elderly, started filtering in early afternoon to a massive park, where police had approved a public gathering.

But the crowds were so big that they spilled out into side streets, eventually marching peacefully through several neighbourhoods. Some chanted slogans like “Hong Kong people, add oil!” while others waved signs that read, “Our spirit will never die!”

Organisers estimated 1.7m protesters turned out, with police putting the number at just 128,000.

As a downpour suddenly started, a pizza parlour began handing out free slices, and taped signs to the window: “Cheer Up, Hong Kong.” Nearby a bakery’s shelves were wiped clean as some protesters seeking brief refuge from the rain grabbed snacks.

Hong Kong is embroiled in its worst political crisis since the former British colony was returned to Beijing rule in 1997. Protesters first took to the streets against a now-suspended extradition bill that would have sent people to face trial in mainland China, where Communist Party control of the courts contributes to a 99.9 per cent conviction rate.

Still, people stayed in the streets, demanding the government formally withdraw the bill to prevent lawmakers from quickly tabling and passing the legislation in the future. Their calls have also expanded to include broader reforms, such as direct leadership elections.