A secret Government report has revealed that a no-deal Brexit could have a "life-threatening impact" on patients in Northern Ireland.
The Department of Health has been planning for a series of devastating disruptions to the NHS in the event of the UK crashing out of the EU, according to its previously unseen document.
Among the issues included in the list of "reasonable worst case" scenarios are shortages of vaccines and medication, including some cancer therapies; difficulties running the children's heart surgery service, and more than 1,000 NHS employees being unable to get to work or quitting their jobs.
The dossier, marked "official sensitive", has been leaked after health officials refused to make public the contingency plans they are putting in place to mitigate the effects of a no-deal Brexit.
After a Freedom of Information request, the Belfast Trust had refused to release details of measures being implemented to protect patient safety following a no-deal Brexit, stating that it could cause alarm and confusion.
However, the Belfast Telegraph can now reveal the contents of the Department of Health's report, which Alliance Party health spokeswoman Paula Bradshaw has described as "life and death" issues.
It reveals that in January officials still had to take action to ensure there will be adequate stocks of 300 medicines, with 28 "that appear problematic".
It said that departmental officials have been "engaging with the relevant suppliers for these lines to confirm ability to stockpile or identify alternative suppliers".
They have also been developing an action plan should a supply gap occur, which would be "likely to have a life-threatening impact on patients" and would require assistance from the police.
Alternative ferry routes have been developed, while priority status will be given to medicines and medical products to help prevent a medication crisis.
The department has also been stockpiling three to six months of vaccine supplies, while officials have been carrying out an exercise to establish which medical trials may be affected by a no-deal Brexit.
The document said: "Volumes of medicines involved in clinical trials are small but the proportion that require special transit due to cold storage or short life is disproportionately high."
Movement of patients across the border has also been identified as an issue, which has the potential to affect people who suffer major trauma in border areas, children and babies who need emergency heart surgery, and a specialist unit at Altnagelvin where patients who suffer heart attacks undergo lifesaving surgery.
The document said the position depends on the withdrawal agreement and border arrangements.
Cross-border services, such as Altnagelvin's radiotherapy services and kidney transplant operations, may also be affected.
There may also be problems with paramedics working on either side of the border, which is particularly significant as it comes just weeks after the Northern Ireland Ambulance Service turned to colleagues in the Republic of Ireland to respond to 999 calls here due to staff shortages.
The report also states that the Business Services Organisation has stockpiled 10 weeks of medical consumables, which includes the likes of infection control equipment, and is being stored at the Northern Ireland Fire and Rescue Training Centre in south Belfast. Should a critical shortage occur despite this, a national response will be triggered. The report also reveals that health officials, who are already struggling to deliver services with their current budget, need an additional £16m to mitigate the increased costs of medical supplies.
The document also deals with the potential effects on the NHS workforce and reveals a no-deal Brexit may result in an increased reliance on overtime, agency and bank staff.
The report warns that 750 frontier staff, including nurses, midwives, doctors, allied health professionals, and an additional 400 independent social care workers, may experience difficulty getting to work as a result of civil unrest, vehicle checks or problems with car insurance or driving licenses.
It explained: "There is the potential for service disruption if, for example, domiciliary care workers in border areas, who very frequently cross the border during their shifts, have doubts about the validity of driving licences/car insurance, etc."
It also warns that NHS staff who live in the Republic of Ireland may resign from their jobs, and while numbers are "expected to be small", there will be a "disproportionate impact given high levels of vacancies".
Again, additional funding has been sought to pay for agency staff; however, the document does not provide the likely bill to the health service.
The dossier also revealed that health bosses have been working to establish whether EU engineers will be able to come to Northern Ireland to maintain "important equipment", such as MRI scanners.
Additional car and employer's liability insurance may be required, the document warns, which would also result in further strain on the already overstretched health budget. There has also been an examination into the potential effect of a "substantial number of Northern Ireland citizens" returning here for healthcare.
It has been working to establish the possible impact to ensure adequate resources are in place, but stressed that NHS healthcare will only be provided to those people returning to Northern Ireland on a permanent basis.
Ms Bradshaw said: "The issues raised are literally a matter of life and death for people here, with no guarantees around crucial vaccines and cancer therapies. This is a clear demonstration of why I have demanded detail from the Northern Ireland Department of Health and trusts and I have now to query what else they are hiding from the public.
"Let us also remember that the DUP believes that threatening lives in Northern Ireland is a reasonable negotiating tactic and, it was revealed clearly by Amber Rudd on Saturday, is propping up a Government which is spending more time on no-deal, with all the devastating and life-threatening consequences, than on actually getting a deal which would secure supplies, equipment and staff.
"Such a callous disregard for lives and livelihoods in Northern Ireland is shameful."
In response, the Department for Health said it "appreciates this is an uncertain time".
"We would emphasise that intensive contingency planning for Brexit is a major priority within the department and across the HSC system," it said.
"No immediate impact is anticipated on the day-to-day provision of health and social care services. Furthermore, structures and processes have been put in place to deal with any potential disruption should it occur.
"Arrangements are in place for medicine supplies for Northern Ireland. There is no need for anyone to change the way that they order prescriptions or take their medicines.
"The Department of Health website is updated regularly with information and advice on Brexit. In addition, the department is planning further communication and engagement events starting this week and political representatives have been invited to meet with the department.
"The department assures the public that their safety is our priority at all times."