Pharmacy Voice, which represents High Street chemists, says that without access to a community pharmacist one in four people would visit their busy local GP instead.
But the government says outlets in some areas are too close together.
It proposes giving more people access to a community pharmacy.
The Department of Health in England says the average community pharmacy receives about Â£220,000 in NHS funding each year.
It also says too many chemists are too close to each other, with 40% located in clusters of three or more within a 10-minute walk of each other.
As a result, the government proposes cutting the amount of funding some receive, which would reduce its bill by Â£170m.
The number of pharmacies has grown by a fifth since 2003.
Under the proposals, more NHS funds would be provided to certain pharmacies to make sure everyone has access to a community pharmacy.
Pharmacy Voice says its members play a key role in providing community healthcare, and relieve pressure on hard-pressed GPs.
It says the government plans would mean the closure of up to 3,000 community pharmacists, particularly in deprived areas where there is a higher concentration of shops, but also where the need for their services is greatest.
Prof Rob Darracott, chief executive of Pharmacy Voice, said: "People are increasingly aware of the role a local pharmacy plays in not just dispensing their medicines, but in dispensing vital health services.
"Advising and helping people to treat minor ailments is a starting point, but increasingly, pharmacy is playing a key role in helping people lead healthier lives through interventions like smoking cessation and weight management programmes.
"These are important stepping stones to increasing life expectancy in some of our most disadvantaged communities.
"Losing a local pharmacy in these areas is simply not an option."
About 80-90% of an average High Street pharmacy's funding comes from the NHS.
A public consultation on the proposals closes on Tuesday.
Dr Keith Ridge, chief pharmaceutical officer in England, said community pharmacies were a vital part of the health and care system.
"That's why we are consulting on changes that will better integrate pharmacy into the NHS. We are looking at ways to make greater use of the skills of pharmacists in GP surgeries, A&E, care homes and other settings, and make better use of technology.
"These proposals will ensure we have a modern, efficient pharmacy sector which gives patients the support of pharmacy services when and where they need it."

Sum: Thousands of local pharmacies in England are at risk of closure because of cuts by the Department of Health, a campaign group has said.


Two houses were badly damaged in the blaze at Tirellan Heights in the city.
The fire broke out at about 05:45 local time and six people escaped from the two houses.
Nearby homes were also evacuated as fire fighters worked to extinguish the flames. There were no reports of injuries. The cause of the fire is under investigation.

Sum:
Six people have escaped injury in an overnight fire in Galway.