The BMA's UK junior doctor committee voted not to re-enter contract negotiations with NHS Employers, with the union claiming the current offer is "unacceptable".
Health Secretary Jeremy Hunt has given the BMA until September to negotiate changes to working contracts for hospital consultants and junior doctors to ensure "proper" seven-day services, warning that he is ready to impose a new contract if they cannot agree.
NHS Employers chief Danny Mortimer said: "We understand the BMA concerns about the recommendations and how they might be implemented, but working through these together is the best way to get the most suitable outcome for patients and doctors.
"While the Doctors and Dentists Review Body endorsed the broad direction of travel, there was still much to do, and we accepted their encouragement to discuss these issues - including the BMA concerns - further."
The proposed revision of the whole pay system, includes:
• higher rates of basic pay
• a standard 40 hour week and a lower cap of no more than 72 hours work in any 7 consecutive days
• higher rates of pay for night work in return for more hours paid at standard rates
• improved pension benefits
However, Dr Kitty Mohan, the BMA junior doctor committee co-chair, countered: "The Government has said it wants to negotiate but this 'offer' on the table is an imposition in all but name. It would be letting down our members and the patients for whom they care to simply go along with a Government hell-bent on getting something signed, sealed and delivered as quickly as possible.
"This is simply unacceptable. Junior doctors are not prepared to agree contract changes that would risk patient safety and doctors' well-being. This was our position in October and - in the absence of any attempt by the Government to address our concerns - remains our position today.
"We want a contract that is good for patients, fair for doctors and good for the NHS. That means instead of imposing changes on junior doctors, the Government should put aside its artificial deadlines, its imposed recommendations and work with the BMA on genuine negotiations."