The length of Hong Kong’s protests has become as remarkable as their breadth of participation. As many as one in four inhabitants have taken to the streets and this week – two and a half months after the movement began – it became the longest-running political protest since the handover. But the longer the demonstrations go on, the harder it has become to see a way out.

This month, following the occupation of the airport, both police and activists stepped down their tactics. The resulting period of peace, which included a march by 1.7 million people, gave authorities an opportunity to look for a way out of the impasse. To no one’s great surprise, they did not take it. Though most protesters still shun violence, escalation has resumed, with a policeman firing a live round during clashes for the first time and some on the streets lobbing molotov cocktails.

A ban on what was expected to be another huge march on Saturday has raised tensions further despite hopes that a compromise could still be found. Meanwhile, there are suggestions that authorities might invoke the Emergency Regulations Ordinance, a colonial-era law giving the chief executive sweeping powers of censorship, suppression of publications and communications, arrests, deportations and property seizures. Rumours suggest the government may be testing the waters, with a view to specific actions such as introducing internet censorship. The spectre of a still grimmer outcome looms.

Activists have diversified their approach to maintain momentum. Last week saw a 30-mile human chain. They hope to keep the pressure up with a class boycott when schools and universities resume next week and another mass event on the extremely sensitive date of 1 October – when the Communist party will celebrate the 70th anniversary of its rule.

But the durability of this movement owes at least as much to its opponents as to its supporters. Despite the unfounded accusations of foreign meddling, this crisis was made in China. Authorities may have hoped that a campaign of attrition would gradually wear out protesters. But Beijing’s threats, Carrie Lam’s intransigence and tone-deaf public statements, and police brutality have so far fired up those already involved and brought more into the fold.

A campaign triggered by the extradition bill has become far broader. More than three-quarters of the city’s population now oppose Ms Lam as chief executive – a record low for a leader in its post-colonial history. When campaigning for the job she insisted that she would resign if the mainstream view so dictated. Now she says it is her responsibility to continue to hold the fort which is disintegrating around her. She has made no concessions since announcing the bill “dead”, though even pro-establishment figures have urged her to withdraw it formally and hold an independent inquiry into the police handling of the unrest. The assumption is that the choice is not hers to make. Protesters took vague proposals of dialogue as simply a stalling tactic and she herself insists that she will not budge on their demands.

The G7 was right to reaffirm the importance of the Sino-British joint declaration – which guaranteed that Hong Kong’s way of life would be maintained until 2047 – in its joint statement from the Biarritz summit. Beijing reacted with predictable hostility, but other countries should not be deterred. The risks are real and the people of Hong Kong have very little on their side. They need the international community’s attention and support.