GPs say patient safety is at risk due to "unmanageable" workloads.
A survey of 5,025 family doctors for the British Medical Association (BMA) found 57% felt their workload was unmanageable, with a further 27% saying it was excessive.
This prevented GPs from delivering high quality and safe care to patients at times, the survey found.
The South East and the West Midlands both had 86% of doctors saying their workload was unmanageable.
Only 10% of those surveyed across England thought their workload was manageable and enabled them to offer good quality and safe care.
Dr Chaand Nagpaul, chairman of the BMA's GP committee, said: "This major survey of more than 5,000 GPs in England demonstrates that GP practices across the country are struggling to provide safe, high-quality patient care because of unmanageable workload.
"Many practices are being overwhelmed by rising patient demand, contracting budgets and staff shortages which has left them unable to deliver enough appointments and the specialist care many patients need.
"Addressing the crisis in general practice requires a clear strategy that tackles the numerous problems undermining local GP services.
"We need an urgent expansion of the workforce in both practices and community-based teams, with GPs calling for an increased number of nurses to look after housebound patients and mental health workers to cope with growing demand in this area.
"Better information for patients about how to safely self-care and wider funding increases for general practice are also needed."
In the survey, GPs called for more community nursing for housebound patients (cited by 64%), more help so patients could manage conditions themselves (59%) and more mental health workers in the community (53%).
The Royal College of GPs has also made repeated calls for more staffing and money to be put into general practice due to "the unsustainable pressures of rising demand and a diminishing workforce".
It has argued that patients are also living longer than before with multiple, long-term conditions, which means GP workload is growing in complexity as well as volume.
A Department of Health spokeswoman said: "We are investing in primary care precisely to relieve pressure on the frontline, which will improve patient safety - with an extra £2.4 billion of funding, 5,000 more doctors in general practice and 1,500 more pharmacists in surgeries by 2020. We're expanding the workforce so well-resourced GPs can give even higher standards of care."