Health Minister Peter Dutton says the government will push through a smaller Medical Research Future Fund if its embattled GP co-payment fails, as business and medical researchers raise the pressure to get the proposed $20 billion fund over the line.

''The medical research future fund without the co-payment will be much smaller, no doubt about that,'' Mr Dutton said on Sunday.

Federal Minister for Health Peter Dutton. Credit:Getty Images/Darrian Traynor

''If the co-payment falls over, then that is going to be a big blow to the medical research future fund.''

The government has said $5 of the $7 co-payment will be put towards establishing a $20 billion research fund, with some other health savings contributing to the fund's initial investment.

Mr Dutton said the co-payment was the biggest source of funding for the research fund but another three sources from the budget would contribute to its start-up.

The fund is unlikely to get through the Senate, but business leaders and the medical research sector have set up a lobby group to build a case for it.