But ministers argue that the BMA had agreed to the introduction of online booking as part of a new negotiated contract in England. They point out that many GPs already offer the service.
Wes Streeting, Secretary of State for Health and Social Care, said it was "absurd" that in 2025 many patients can't request appointments online.
"If you can book a hair appointment online, you should be able to book an NHS appointment too. We have agreed clear safeguards, where patients will be directed to phone up or attend in person for urgent appointments. The BMA knows this. This government will always put the interests of patients first, and we will not stand for our NHS being held back in the analogue age."
Dr Katie Bramall-Stainer, chair of the BMA GP committee, said the changes were agreed to "on the condition that 'necessary safeguards' would be put in place" before Wednesday 1 October.
"This was agreed – in writing – with government… and NHSE in February this year. Now almost eight months later, it is deeply disappointing to see promises broken," she added.
She said ministers had been warned that the changes would lead to "hospital-style waiting lists in general practice" which could "reduce face-to-face GP appointments".
Mr Streeting said that that 2,000 extra GPs had already been hired across England and that patient satisfaction with their GPs was on the up.
Officials said that surgeries which had implemented the changes had reported reduced waiting times for appointments.