Nurses working at Lancashire Teaching Hospital's Chorley and South Ribble Hospital have put the trust on notice.
Staff working in the Accident and Emergency Department at the Chorley and South Ribble Hospital have written to bosses calling for the trust to address serval issues in service provision.
The emergency department at the Chorley and South Ribble Hospital was temporarily closed due to "staffing issues" in 2016 but reopened nine months later on a part-time basis - it now operates between 8am to 8pm, seven days a week.
However, staff working in the department claim that there are still failings within the service provision.
Staff claim to be working 17-hour shifts just to ensure patients are seen, treated and admitted and claim to have raised concerns about the safety of staff and patients multiple times with no action from the trust.
In a letter written to senior managers, they write; "some site managers have used unfair coercive tactics to get us to stay. We have been threatened with disciplinary action, breaching NMC code of conducts and dereliction of duty.
"As caring professional, we have persevered with this inadequate situation for the last year but have now reached a point where we are unable to continue with this uncertainty for we fear burnout".
Staff have given Lancashire Teaching Hospital thirty days to ensure adequate service provision is in place before "goodwill" is withdrawn.
Karen Partington, Chief Executive of Lancashire Teaching Hospitals NHS Foundation Trust said, “Last week some Chorley emergency department staff informed the senior team that at times they have been unable to leave work at the end of their shift, because some patients were still present and required care.
“We agree that this isn’t acceptable, and apologise for the disruption this has caused them and their families. We have recently met with staff and the union to hear their views, and have agreed a number of actions to make sure they are able to leave work on time.
“We regret that on occasion some patients have remained in the emergency department for longer than they should. This is a direct consequence of our wards being exceptionally busy which causes delays admitting patients from the emergency department – extending the opening hours at Chorley would not resolve this problem.
“Our emergency department staff at both Chorley and Preston, together with the wider health and care workforce are working hard to provide effective treatment during this very busy period, and we thank them all for their continued dedication and compassion.”