Talks aimed at averting next week's NHS strike have adjourned and will resume on Monday, unions have said.
The GMB union has issued formal notice of a strike by health workers planned for 29th January.
It comes as union officials return to talks with the Government later today aimed at averting industrial action.
GMB said it had served NHS employers in England and Northern Ireland with the necessary information about the stoppage involving hospital and ambulance workers.
Ambulance members of the union will strike for 24 hours from 0001, while other health workers will take action for 12 hours from midday.
Members of Unison and Unite are also set to go on strike on the same day.
The Health Secretary Jeremy Hunt will today chair a meeting of the Government's emergency Cobra committee to put in place contingency plans for an NHS strike.
Talks between union leaders and the Health Department aimed at averting the industrial action are set to continue on Friday.
News of the Cobra meeting came within hours of the talks being adjourned on Wednesday evening.
Health workers across England and Northern Ireland are due to go on strike next Thursday, January 29, in a dispute over pay rises.
Crucial talks being held today in a last-ditch bid to avert a strike by thousands of NHS workers in a bitter dispute over pay.
Today's talks were arranged after a meeting last night between Health Secretary Jeremy Hunt and officials from several unions.
The industrial action in England and Northern Ireland is still planned for January 29 as unions continue to criticise the Government for refusing to accept a recommended 1% pay rise for all NHS staff.
Health unions are hopeful that industrial actions scheduled for next week could be cancelled after progress on a new pay deal, ITV News Political Correspondent Libby Wiener reports:
The Health Secretary has called unions to a meeting ahead of the latest strike planned by NHS workers in their bitter row with the Government over pay.
Sources told the Press Association that officials from several unions had been invited to the talks on Tuesday with Jeremy Hunt.
The meeting comes just over a week before a planned walkout by NHS workers in England and Northern Ireland in protest at the coalition's refusal to accept a recommended 1% pay rise for all staff.
Members of Unison, Unite and the GMB in hospitals in England will walk out for 12 hours between 9am and 9pm on January 29th, followed by a work to rule until February 24th.
Christina McAnea, Unison's head of health, said: "We have been asking for a meeting with the secretary of state since the dispute began.
"We hope the meeting will give us an opportunity to have serious discussions on how to resolve pay and staffing issues."
The medical director of NHS England, Sir Bruce Keogh, will give evidence to MPs today about pressure on emergency services.
The hearing comes after one NHS trust admitted downgrading thousands of 999 calls without permission from senior management.
The East of England Ambulance Service released an internal report showing that 57 patients died after having their 999 calls downgraded leading ambulances to either arrive late at the scene or not turn up at all.
Yesterday, shadow health secretary Andy Burnham raised the case in the House of Commons, claiming that some of the downgraded calls were on behalf of terminally ill patients.
Health Secretary Jeremy Hunt said the East of England ambulance service has received £3.6 million of extra support this winter and defended the record of ambulance services nationwide.
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Labour's shadow health secretary Andy Burnham has said that today's five-year forecast for the NHS "endorses key planks of Labour's plan".
He said he agrees with the report's finding that primary care has been under-resourced and called on the government to stop cuts to the budget for GPs.
Mr Burnham also noted that the report "does not give one mention to competition" and says the Coalition should review its competition rules.
While the Health Secretary denied that the report endorses Labour's vision, he said there were large parts of it that Labour and the Conservatives "can agree on".