Junior doctors are paid less than Pret a Manger workers, claims the British Medical Association, as more than 70,000 are expected to walk out on strike over the next three days.
It is the longest continuous walk-out in the NHS' history and means A&E departments will have only about half their usual staff.
The BMA say they are demanding an end to a decade of below-inflation pay deals.
The BMA says the latest 2023 uplift is just 2% at a time when annual inflation is currently 10.7%.
Launching the campaign, it said: “Pret a Manger has announced it will pay up to £14.10 per hour.
"A junior doctor makes just £14.09. Thanks to this Government you can make more serving coffee than saving patients.”
There are around 80,000 junior doctors in the NHS who start on salaries of between £25,000 and £30,000.
Dr Robert Laurenson, co-chairman of the BMA junior doctors' committee, told Sky News that "our pay range starts at £14 an hour and, after 10 years of practice, you know, seriously skilled and educated and talented people who have gone through many expensive exams, achieving many difficult competencies over their careers...
"So, for example, neurosurgeons operating on people's brains in the middle of night, they can be earning about £28 an hour on that basic hourly rate and our basic hours are quite shocking. Our basic hours range from 7am to 9pm. That's what's called a basic hour for us."
Martin Whyte, 36, a paediatric registrar at the Royal Victoria Infirmary in Newcastle, and a deputy chairman on the BMA's junior doctors' committee, said: "Over the past 15 years we have had a 26% pay cut in real terms which has got us to the point where a newly qualified doctor is paid £14.09 per hour to provide essential out-of-hours and in-hours medical care.
"As a profession, we find this intolerable and it had got to the point where our members have voted overwhelmingly for industrial action.
"We have had lots of people saying they support us."
Edward Finn, an anaesthetist registrar at the Nottingham University Hospitals NHS Trust, said that there was a consistent theme of junior doctors feeling undervalued and that he and his wife - who works in the same role in hospitals across Nottingham - are having to make sacrifices due to real-term pay cuts.
He said: "If you look at the overall cost of living, wages that haven't kept up with that, and we don't go out for meals, we don't do anything.
"My wife and I are both part-time - we couldn't afford to be full-time with the cost of childcare - but we still have to do the occasional extra shift on top of our contracted hours to keep up with things like the electricity bill.
"When you're talking about somebody who's been a doctor for 12 years, it's quite sad really, isn't it?
"I'm a firm believer that there's no good having a race to the bottom, and I think pay comparisons between different sectors are often unhelpful, but at the same time, I've got a cousin who's four or five years younger than me, who is not that much different in terms of qualifications, he's a mining engineer, and he gets easily paid three times what I do.
"He works in the private sector, so obviously it's different, you can't compare apples and oranges, but at the same time, I think it shows you that it's about what you value.
"You can't have a thriving workforce in this country, you can't have growth in this country unless you have good health."
Professor Philip Banfield, the BMA’s chairman of the council, said the “crisis” in the NHS is “seeing junior doctors leave in their droves”.
Speaking on a picket line outside the Queen Elizabeth Hospital in Birmingham, he told PA: “It’s the refusal of the Government to listen to junior doctors and the crisis unfolding in the NHS.
“We have the worst crisis in the NHS that I have ever known and it’s seeing junior doctors leave in their droves.
“The junior doctors’ strike is so sad to see but they feel they have been driven to this.
“No one wants to strike but strike action has to be effective.”
He added: “What is going on day in, day-out is that patients are dying.
“The Royal College of Emergency Medicine estimates that between 300 and 500 people are dying unnecessarily, because of the state of emergency departments across the UK, per week.
“That is an absolute national scandal.”
