New figures from the HSE show that just one in seven hospital consultants on the new public-only contracts are working on a Saturday, while just one in three are working extended day shifts.
It comes as hospitals prepare for increased pressure over the winter months.
The Public Only Consultant Contract was delivered more than three years ago and was designed to make better use of clinics and operating theatres in hospitals.
It was also implemented to increase the number of consultants available to treat patients outside Monday to Friday hours.
However, the latest figures show the change is happening slowly.
Over 3,200 consultants who have signed up to the public-only consultant contact recorded their hours.
The HSE figures show 14% of these are working on Saturdays and just 38% are working extended day shifts.
Social Democrats Spokesperson on Health Padraig Rice said consultants that signed public-only contract must adhere to them and implement them in full.
“It’s unacceptable that only one in seven hospital consultants on the new contracts are working on the weekend.
“A core part of the reform under the new public-only contract was extended hours on evenings and weekends, the consultants who signed those contracts must adhere to them and implement them in full.
“We have seen now repeated breaches of these contracts and its utterly acceptable and we need to see this changed.”
Padraig Rice TD called on the Government to lift the recruitment embargo for hospitals
“We heard this week that there are hundreds of vacancies in Cork University Hospital alone and this is repeated in hospitals right around the country.
“I’m calling on the minister for health to lift the de-facto recruitment embargo to allow hospitals to hire the staff they need so that we can create a seven-day health care service.”
The Irish Medical Organisation says additional staff and resources are needed at weekends to support consultants.
Professor Mick Molloy, Consultant in Emergency Medicine and Chair of the IMO consultants Committee, said: “If you want to roster scheduled work such as outpatients’ clinics at weekends, it does require a team of people to make that work effectively.
“You can bring a consultant in and you can run a consultant only clinic where there may not even be an administrator and there may not even be a nurse to help them and they can see far fewer patients than they would in a routine clinic.
“You now roster that person to work on a Saturday so you then have to take another day during the week and de-roster them… now in a scenario where patients have been given outpatient appointments for a year or two years in advance, you’re now cancelling patient clinics on another day and it will not serve the purpose that was intended unless we get sufficient staff to run all these clinics.”