A strike of junior doctors will go ahead next week as planned, after ongoing talks did not manage to resolve the dispute over contracts.
The meeting between the British Medical Association (BMA) and NHS Employers were "constructive", but unable to prevent industrial action beginning on Tuesday, the Advisory, Conciliation and Arbitration Service (Acas) said.
On Monday, the BMA announced three spells of strike action in England after negotiations with the Government ended with no resolution.
Talks will continue next week in a bid to stop further days of strike action taking place.
Junior doctors are set to provide emergency care only from 8am on Tuesday.
The strikes will lead to disruption for thousands of NHS patients. Suspended strike action in November led to the cancellation of thousands of operations, procedures and appointments.
Some of the areas disputed by the BMA include the issue of weekend pay.
Health Secretary Jeremy Hunt has said the talks on Monday lasted less than an hour before BMA doctors walked out.
An Acas spokesman said: "Talks have been held under the auspices of Acas between the established team for the BMA and the NHS team.
"A very helpful stock-take of issues took place. Unfortunately, whilst talks have been constructive and will continue next week, the parties are not able to prevent the industrial action planned for January 12 2016."
Tuesday's strike will be followed by a 48-hour stoppage and the provision of emergency care only from 8am on January 26.
On February 10, there will be a full withdrawal of labour from 8am to 5pm.
It was hoped that industrial action could have been called off at the 11th hour if a settlement could be made. Strikes were suspended at the last minute on November 30.
Negotiations centred on the Government's offer from early November, including an 11% rise in basic pay for junior doctors.
This is offset by plans to cut the number of hours on a weekend for which junior doctors can claim extra pay for unsocial hours.
Currently, 7pm to 7am Monday to Friday and the whole of Saturday and Sunday attract a premium rate of pay.
Under the Government's offer, junior doctors would receive time and a half for any hours worked Monday to Sunday between 10pm and 7am, and time and a third for any hours worked between 7pm and 10pm on Saturdays and 7am and 10pm on Sundays.
Junior doctors would also receive on-call availability allowances, ranging from 2% to 6% of basic pay, as well as payment for work undertaken as a result of being on-call.