The country's powerful pharmacy lobby is threatening a damning public campaign against the Turnbull government if it doesn't settle a bitter funding dispute in its favour.

The Pharmacy Guild of Australia has embarked on a lobbying blitz of Coalition backbench MPs to pressure Prime Minister Malcolm Turnbull and Health Minister Sussan Ley into changing course.

Health Minister Sussan Ley says the government is working towards a "mutually satisfactory outcome" over a funding dispute with the Pharmacy Guild. Credit:Andrew Meares

The guild and the government are locked in an arm-wrestle over some elements of an $18.9-billion funding deal with the guild and the 5500 community pharmacies it represents.

Called a "risk share", the contested element forecasts prescription volumes in each of the pharmacy agreement's five years. In the first year – last financial year – there was a 2.1 per cent shortfall in prescriptions, delivering the government a saving of up to $500 million.