The Minister for the Environment is being called on to legalise a grant scheme that helps householders protect their homes against radon gas.
Minister Cullen is being asked to sign into law the grant scheme because nearly 10% of homes are thought to have unacceptable levels of radon.
Next to smoking, long-term exposure to radon gas in the home is the greatest single cause of lung cancer in Ireland.
The radioactive gas is a natural occurring substance from rocks and soil.
While it is harmless in open air, it is dangerous in enclosed spaces or indoors.
It is now thought that almost 91,000 Irish homes probably have radon levels above what is the recommended amount.
However, according to the Radiological Protection Institute of Ireland, only 2,500 of these have been identified.
Martin Cullen is expected to be asked to sign the checking scheme into law when the National Radon Forum holds its inaugural meeting in Dublin today.