Welsh Conservative and Shadow Health Minister Russell George explains the FOI findings and what action he wants to see taken.
Staff shortages across A&E departments are putting patient safety in a "very unsafe position" according to the Welsh Conservatives.
A Freedom of Information request conducted by the party found that the shortfall in staffing levels is the primary cause of the A&E crisis.
Figures revealed every major hospital is falling short of the recommended 'baseline' for staffing levels in emergency departments.
The Royal College of Emergency Medicine sets the ‘baseline’ at 40% for the number of consultants which should be employed in the department to guarantee safe cover.
However, currently, no hospitals meet the criteria which puts "patients in potential danger".
Welsh Conservative and Shadow Health Minister, Russell George, said: "The findings show that we're in a very unsafe position in terms of patient safety in our Wales hospitals."
He added: "The Welsh Government often tell us that there are unprecedented levels of staffing but the issue here is there are 3,000 staff vacancies across the NHS".
However, the Shadow Health Minister believes this was very much the situation "well before" the Covid-19 pandemic.
The Welsh Conservatives have said that a dedicated vaccination minister could help ease pressures.
"I think the Welsh Government needs to have a vaccination minister because at the moment the Health Minister is being pulled in two directions - an NHS crisis on the one hand and the vaccination rollout on the other."
They also believe there could be a better use of community pharmacies and that GPs need more support.
"We know last month we had the worst A&E waiting times on record. We had the longest ambulance response times ever recorded in the UK in the NHS and the longest waiting times for patients to receive treatment."
"We know that the Royal College of Nursing had a campaign saying they were in short of 1,700 nursing staff across Wales so we know that we're desperately understaffed across Wales."
"We've got to at some point, learn to live with the virus."
The research showed that the most understaffed A&E units were in the Cwm Taf Morgannwg health board area that serves the Valleys and Bridgend.
In these areas, all three of its majority hospitals recorded staffing levels between 32% and 35% of the recommended baseline. This meant it had three of the four lowest in Wales.
Ysbyty Glan Clwyd in Denbighshire and Withybush Hospital in Haverfordwest also had numbers under the baseline at 34% and 39%.
In addition, Merthyr Tydfil's Prince Charles Hospital only had 8 funded consultants, less than half of the 18 recommended by the RCEM.
Following the recent findings, Cwm Taf Morgannwg health board said it had recently increased the numbers of staff throughout emergency departments and "continue to look at how we can expand our teams even further".
The health board added: "We would like to reassure our patients that staffing levels in all of our emergency departments are reviewed on a daily basis to ensure that we provide safe and effective care."
"Following a recent review by Healthcare Inspectorate Wales (HIW), we have made further changes to staffing levels within Prince Charles Hospital and are working on a new staffing model to help accelerate some of the changes that were already underway prior to the review."
Doctor Rob Perry, Vice-Chair of the Royal College of Emergency Medicine Wales speaking to Andrea Byrne on Wales at Six.
In response to the FOI, a Welsh Government spokesperson said: "All Health Boards have put in place plans to deal with winter pressures and the pandemic, which includes ensuring emergency departments are staffed by a multi-disciplinary workforce to meet the expected demand.
"Staff illness and Covid-related absences have had a significant impact on staffing levels in recent months, but we are committed to ensuring accident and emergency departments have significant numbers of staff to ensure safe care for people.
The Welsh Government have also announced a £260m plan to train healthcare professionals across the country.
"The investment for 2022/23, which is a 15% increase from 2021/22, will see the highest ever number of training opportunities in Wales.
"This shows our commitment to training the next generation of healthcare workers and providing the necessary resilience and capacity to NHS Wales."