A legal challenge over the Health Secretary's imposition of a new contract on junior doctors working in the NHS in England has reached the High Court.
Campaign group Justice for Health, which was founded by five junior doctors in March, is accusing Jeremy Hunt of acting outside his powers.
The group's application for judicial review is being aided by donations from thousands of members of the public via crowdfunding website Crowd Justice.
Mr Justice Green is conducting a case management hearing in London.
The junior doctors dispute led to the first full walk-out strikes of their kind in British history. Junior doctors rejected the latest contract offer put to a referendum by the BMA in June.
The Health Secretary decided for a second time to impose the contract, leaving junior doctors complaining that their concerns that it was "unsafe and unsustainable" had been ignored.
When he made his decision, Mr Hunt said it had been "difficult " to take but the NHS needed certainty, including in light of the UK's decision to leave the EU.
He made it after junior doctors and medical students rejected a contract brokered between the British Medical Association (BMA) and the Government, with 58% voting against the deal while 42% voted in favour.
Some 68% of those eligible turned out to vote - around 37,000 junior doctors and medical students.
In a Commons statement, Mr Hunt said: "In May, the Government and NHS Employers reached an historic agreement with the BMA on a new contract for junior doctors after three years of negotiations and several days of damaging strike action."
He said the contract was seen as a good deal by Dr Johann Malawana, who was then chairman of the BMA's junior doctors' committee, and was endorsed by royal medical colleges.
He added: "Unfortunately because of the vote we are now left in a no-man's land that, if it continues, can only damage the NHS."
Mr Hunt said the "only realistic way to end this impasse" is to bring in the contract that was agreed with the BMA in May, with the phasing in starting in October.
Under the proposed deal, Saturdays and Sundays would attract premium pay if doctors - the vast majority of whom are expected to - work seven or more weekends in a year.
Doctors would receive a percentage of their annual salary for working these weekends - ranging from 3% for working one weekend in seven to up to 10% if they work one weekend in two.
Any night shift would also result in an enhanced pay rate of 37% for all the hours worked.
The deal also set out payment for doctors who are on call, and agreed a basic pay increase of between 10% and 11%.