Leading medical researchers have urged politicians not to let the federal government's proposed $20 billion fund for medical research become a victim of the divisive debate about the $7 GP co-payment fee.

Researchers, including immunologist and former Australian of the Year Gustav Nossal, admit their advocacy for the fund has been stifled by how it will be financed.

"This is a visionary idea for our children and grandchildren," Sir Gustav said. "I'd urge politicians with every fibre of my being to pick this idea up and run with it.

"The debate has been muted because many people have been antagonistic to the co-payment [but] the potential for the Medical Research Future Fund is absolutely tremendous.

"This would allow us not just independence from the day-to-day decisions of the government but give us the capacity to engage in longer-term and somewhat riskier research that would have a long-term pay-off.