Providing routine health services seven days a week is "not feasible", leading doctors have said.
The prospect of providing services throughout the week would not be possible in the NHS's current financial climate, delegates at the British Medical Association's annual conference In Harrogate said.
If routine and elective services were provided at the weekend it could lead to the reduction of services provided from Monday to Friday or the closure of hospitals, they warned.
Doctors at the meeting voted for a motion saying that seven day urgent care must not be conflated with seven day access to routine services.
They said that provision of such services would require investment and "not merely the reorganisation of services".
Meanwhile doctors should be compensated for working outside of their normal working hours, delegates were told.
They should be paid a "premium" for providing such services, they added. Psychiatrist Professor Reinhard Heun, who introduced the motion, said: "We can't just do the same services which we would do during the week at the weekend - our services are quite stretched anyway.
"If you provide seven day services, which the BMA supports, then we need some investment."
He added that there is "no point" in doctors providing routine services at the weekend if there are no support staff, such as lab technicians and extra nurses, in place to help.
And the medical profession should be "family friendly", he said: "(Doctors) should be able to have time (with their families) and should be able to go on holiday.
"In my view we want the brightest and most motivated people to be medics and they might possibly think 'this is a hurdle and I am not going (to do it) unless there are precautions and conditions which make it easier'."
He added: "You might have to recruit more people and sometimes you have to pay a premium to get people motivated. "This is about fair pay and people have extra expenses covering the weekend and travelling more."
Dr Robert Harwood, of the British Medical Association's consultants committee, added: "We have real reservations on whether or not it can be afforded within the current NHS budget.
"It's about whether or jot there are enough resources in the system to deliver all of your aspirations.
It's no surprise that if you want more service that costs more money."
An NHS England spokeswoman said: "Patients should receive high quality care whenever they need it, and we agree with the many doctors who are working to ensure urgent and emergency care standards are the same on weekends as the rest of the week.
"NHS England is delighted so many doctors and nurses support moves to ensure senior decision makers are available to assess and treat patients whenever they need it."