A survey suggests that only 3% of GPs will definitely take part in the Government's plan to provide free GP care for five-year-olds and under.
The survey of 720 GPs was conducted by the National Association of General Practitioners.
It found that GPs believe the scheme as currently structured by the Government may not have enough doctors to operate.
Of those surveyed, 41% said they will definitely or probably not take part in the scheme as it is currently structured.
The NAGP is to brief the Fine Gael health committee this evening on the findings.
Free GP care for five-year-olds and under is due to come into effect in the middle of the year.
The Government has said it will be an "opt-in" system for GPs.