The National Association of GPs has said its legal advice is that the proposed new scheme for free GP care for all children under the age of six would involve a clear breach of the existing GP contract.
The association says the issue relates to the HSE being permitted to take away patients aged under six from GPs who refuse to sign up to the new deal and give these patients to a doctor who joins the scheme.
In advance of a meeting of GPs in Portlaoise this evening to discuss the issue, the NAGP said it was looking at its legal options on the issue.
The meeting is open to all GPs, whether they are members or not.
The NAGP is planning to ballot GPs on the proposals and until then, it is advising GPs not to rush into any decision.
The Health Service Executive has said it wants GPs to decide by 25 May whether to sign up to the new scheme.
It said there are no figures for the number of GPs who have signed up at this point, given contracts were issued only recently.
The executive said GPs have been asked to return signed contracts no later than 25 May, to ensure their patients are able to register on their panels from early June.
The HSE wants the new service to start from 1 July.
As GPs are independent contractors, they must decide for themselves if they want to sign up or opt out.
Where a GP opts out, their under-six patients will be moved to a doctor who has accepted the deal.
Depending on how many GPs sign up and where, there could be gaps in the country for patients.
Under the new contract, GPs will be paid €125 per child each year, along with other fees.
Children under six will have two basic health checks, at ages two and five.
GPs have to provide a programme of care for children with asthma.
The whole scheme is expected to cost around €67 million this year.
Another union, the Irish Medical Organisation, has said the deal is good for doctors, patients and the State.
