The current funding formula would be relaxed to make it easier for practices to access the scheme, while existing practices would be able to cut fees further or enhance services, he said.
The remaining $20m from the funding increase would be used to boost maternity services and funding to health NGOs -- including mental health practitioners.
Labour's health spokeswoman Annette King said mental health NGOs had not received a funding increase for the past five years.
"You're now seeing some real problems in terms of provision. Some services are closing and they're under tremendous pressure."
Primary health care saved money down the track, Mr Cunliffe said.
"There are significant benefits to society if we can prevent or minimise the impact of illness early on.
"In addition to this $60 million lift to primary health care, a Labour Government will also invest a billion dollars a year into maintaining and improving other vital public services in health and in education.
"Labour has always believed the ability to pay shouldn't be a barrier to people getting healthcare when they need it."
The funding increase would come from Labour's "full alternative budget", Mr Cunliffe said.
Further health policy announcements would be made at Labour's official campaign launch this Sunday, he said.