GPs in England could launch a work-to-rule which would see them limit the number of appointments each day.
NHS England has warned there could be disruption across the NHS if action is taken.
The results of the British Medical Association (BMA) ballot will be announced on Thursday – with scope for the action to start immediately.
The union balloted its members over what it says is a lack of funding.
The BMA has argued GPs are not getting enough to provide safe care, with some practices at risk of closure.
Last month, NHS England wrote to senior managers across the NHS to warn that if action was taken, it could cause significant disruption beyond just GP services. This would include increasing pressure and waits in A&E, slowing down the discharge of patients to hospital, and disrupting referrals into hospital for planned treatments, like hip and knee operations.
The letter warned that, as with other disputes, “maintaining services for patients with urgent needs, such as deteriorating conditions” was key.
The BMA is suggesting a range of different actions could be taken by GPs, but it will be up to GPs themselves to decide what they want to do.
One option is to limit the number of patients they see to 25 a day – which the BMA deems to be the safe level. It is common for GPs to see more than 30, sometimes more than 40 a day.
GPs could also refuse to carry out tests and assessments for hospitals pre or post-treatment and could ignore guidelines on rationing treatments that are put in place to allow the NHS to prioritise the most in-need patients.
The BMA believes none of this action will put GPs in breach of their contract. GP practices are essentially independent businesses, so they are paid a lump sum by the NHS to deliver care and therefore are not directly employed.
BMA members are widely expected to back action – in a vote earlier this year more than 99% voted to reject the funding on offer. Around two-thirds of GPs are thought to be BMA members.
When the ballot was launched, BMA GP leader Dr Katie Bramall-Stainer said the union had been warning for some time that without “drastic improvements” to funding, GPs would be forced into taking action.
She said: “The care GPs want to provide and the services patients want to receive are the same. GP services have been eroded to the tune of hundreds of millions of pounds in recent years.”
The BMA said it would not be making any comment until Thursday when the results of the ballot were unveiled.
