The sound of angry chanting reverberating down Whitehall has become a common theme of the past five years, but there was something special about the protest that gripped the area last Monday. It marked the moment when thousands of Junior Doctors and medical students turned to open revolt over changes to their contracts proposed by Health Secretary Jeremy Hunt. The British Medical Assocaition, the union and professional body which organises doctors, looks set to ballot for major strike action. Within days of it being called, ten thousand have already said they will attend another demonstration on 17 October.

“A majority of people there on Monday were at their first demonstration,” says Sophie, a medical student in London who has been part of organising the protests. The changes to contracts will mean drastically longer working hours for doctors, and big reductions in pay as well – measures which campaigners say will demoralise clinicians and endanger patients. These changes are driven by underinvestment – a need to fulfil the Conservatives’ election pledge for a “seven day NHS” at no extra cost.

There is something about the proposed changed that is pushing the medical profession over the edge. “Everyone already feels so stressed and tired to the bone,” says Sophie. “So to have Jeremy Hunt turn up and tell everyone that the NHS needs to be a seven day service when doctors are already working seven days a week – it just doesn’t fit with people’s experiences.” Sophie tells me that medical teaching staff at her institution have, in defiance of senior managers, sent mass emails to their students urging them to get active in opposing the changes.

But behind the immediate problem of underinvestment, a wider battle is being waged. “Ultimately, this is an attack on the soul of the NHS, which is the goodwill of doctors – and not just doctors, but nurses and other staff as well,” says Anna, a junior doctor working at a London hospital. For Sophie, underinvestment is more than a funding problem: it is a tactic to undermine the NHS itself. “People walk into a hospital that was built in the 1960s and has puddles in it, the computer system doesn’t work, and the staff aren’t functioning properly because they’re being worked until they drop. And funnily enough, it doesn’t look like a very effective system. This is a well-calculated agenda that is aiming at eroding the public’s trust in the NHS.”

Most worryingly for NHS staff, the changes the junior doctors’ contracts look like they are the tip of the iceberg. If the government insists on cutting down on anti-social hours payments to Junior Doctors, they will – as some professional bodies have pointed out – have to justify why similar rebandings should not apply across the board. The grapevine is now full of rumours that the Department of Health is about to announce an analogous set of paycuts for nurses and other clinical staff.

For Anna, the cuts are personal. “Put bluntly, I can’t take a pay cut, which would be a minimum of 15 per cent for me. I will be unable to live where I currently live, and unable to pursue the training course I’m on. I would have to leave London.” Like thousands of other junior doctors, Anna has considered practising abroad as a result of the changes, but in the end has decided to stay put, and to dedicate “every waking moment” to fighting the contract changes.

That is a story which is echoed in hospitals and practices all over the country. The BMA’s membership has ballooned, and anecdotally at least, it seems that the strike will be almost universally supported, not just by junior doctors, but by consultants and the general public as well. The campaign against the changes has taken root in medical schools, meaning that any strike will likely be strengthened by solidarity walkouts from students.

It is perhaps because the contract changes are so personal for doctors that this moment presents such an opportunity for anyone looking to fight for the future of the NHS. Since the Conservatives first came into power in 2010, NHS campaigns have been growing and gaining public attention, but – unlike campaigns against austerity in general, or tuition fees – have yet to manifest themselves as a mass movement of civil disobedience. The junior doctors’ dispute has the potential to provide that catalyst: it is capturing the imagination of a broad section of the public, and, ultimately, it has the industrial power to force the government into a U-turn.

The outcome will depend on how solid the strike is, and on the extent to which the public blames the government – rather than NHS staff – for the disruption that will have to be caused to the health service. If the past week is anything to go by, junior doctors have significant reason to be cheerful.