A "new normal" of reduced cancer services because of new Covid-19 restrictions or insufficient funding would be completely unacceptable, said the Irish Cancer Society.
"Ireland’s cancer community face becoming the ‘forgotten C’ during this pandemic unless action is taken now," it warned.
Media reports on briefing documents prepared by the Department of Health, for new Minister Stephen Donnelly, drew an angry response from the society.
The society's director of advocacy, Rachel Morrogh, said it is clear that the double whammy of chronic underfunding and Covid-19 restrictions could lead to delayed diagnosis and treatment for cancer patients.
She warned that anything less than the full resourcing and investment needed to avoid this situation would be unacceptable.
Ms Morrogh said the warnings from department officials echo calls made by the society in recent years that cancer services are extremely vulnerable.
Long before Covid-19, cancer services have been unable to meet the demand for referrals, a situation that has led to long waiting lists.
“However, with significant and immediate investment in physical space and resourcing, it may be possible to prevent this prediction from becoming a reality," Ms Morrogh warned.
“We urge the Minister to urgently commit the necessary funding to cancer services. The Programme for Government says that the National Cancer Strategy will be fully implemented.
"If a significant investment is not made this year, the National Cancer Strategy will not be implemented and cancer patients will continue to experience worse outcomes than other European countries."
Ireland is currently in the lower half of the Organisation for Economic Co-operation and Development's (OECD) league table of cancer deaths in the EU.
"We need to move from laggard to leader in the area of cancer care.
"Only investment in the National Cancer Strategy will achieve that," says Ms Morrogh.