The Irish Medical Organisation says plans for Free GP care are "doomed" without full negotiations with doctors over resourcing the scheme.
The IMO says Junior Health Minister Alex White's refusal to discuss resources will put "patient safety at risk".
Dr Ray Whalley, the IMO's GP Committee chair, says its support for free GP care depends on having enough financial support from the Government.
He says the organisation may be forced to engage in litigation if the Government goes ahead without further consultation.