Medical staff from across the Westcountry have joined the fight against the creation of a so-called regional pay cartel in the NHS.
The British Medical Association (BMA) and Royal College of Nursing (RCN) say they will not recognise the South West Pay Consortium (SWC), which has been formed to find ways of meeting future economic challenges.
So far, 20 organisations have signed up, including hospitals in Exeter, Truro and Plymouth.
Sue Matthews, regional officer for the RCN, warned that members were angry.
"It is top of the agenda," she said.
"It is the first time I have heard nurses talking about legal action without someone else putting it to them.
"They are disgusted that this secretive cartel was put into place and that those health organisations have joined up."
Mrs Matthews said the RCN was working with other unions to present a joint front and she revealed they were also in discussion about issuing legal proceedings.
"We are talking to our lawyers about the potential for legal action.
"We are pursuing our MPs and we are talking to non-executive directors of hospitals.
"Every avenue will be explored."
The BMA said it would not recognise the SWC and have made it clear that any talks on the pay, terms and conditions of their members must be done at a national level.
South-West regional council chair John Hyslop said: "The logic (of maintaining national pay and conditions) is inescapable when you understand the problems of rurality in recruiting workers in the South West.
"There's no doubt that years of experience have taught us that the NHS relies upon being able to recruit healthcare professionals on a level playing field.
"That, in many ways, explains the stability of the NHS workforce and its apparent productivity." The GMB and Unison have already started a rolling series of meetings with their members.
Recently released documents from the consortium said "absolutely no proposals have been put forward regarding any proposed changes to pay, terms and conditions."
However it goes on to detail a number of "staff cost reduction potential opportunities" including asking people to work extra hours for no extra pay, reducing unsocial hours allowances and reducing sick pay for new starters.
A SWC spokesman said it had been formed in response to the serious financial and clinical service challenges facing the NHS, now and in the future.
"Its aim is to provide greater security for health services and for staff, with an affordable pay, terms and conditions system that recognises and rewards performance and creates a flexible workforce responsive to changing patient needs that is fit for purpose in the modern NHS."