The Labour leader Pat Rabbitte is appealing to both the Minister for Health and building developers not to sign contracts for large private hospitals on public hospital land.
Labour has warned that it will scrap the building of these private clinics on public hospital sites if it gets into government with Fine Gael.
The party says the plans will worsen the two-tier health system by attracting all the best healthcare staff away from public hospital services.
"If we allow, as Mary Harney wants, the construction of super-private clinics on the premises of our public hospitals, it will give advantage to those who can afford to go the private route," said Mr Rabbitte.
"It will further damage the prospects of those waiting in the public health service," he added.