The LMCs Conference in Liverpool supported a motion that supported the principle of longer GP training, but insisted any extension should improve skills in neglected areas, such as out-of-hours training.
The vote follows the RCGP's successful bid last month to persuade the Medical Programme Board to extend GP training to four years.
Pulse revealed last month that GP trainees will be expected to plug service gaps, under plans being discussed with the Department of Health and education leaders.
But the conference said extended training should be fully funded as a full educational and developmental scheme.
Proposing the motion, Dr Julie Ann Birch, member of Cleveland LMC, said: 'We must be clear. Any extension of GP training must be fully funded.'
Dr John Allingham, medical secretary of Kent LMC, said a key part of extended training would be developing better skills in out-of-hours.
He said: ‘A lot of ST3's fudge their out-of-hours. They never actually do them. We need to enhance out-of-hours so the trainees actually do it.'
But Dr Mike Moor, a member of Cambridge LMC, said he was worried that increasing the length of GP training will send the wrong message to those who have already passed their exams.
He said: ‘Their competency may vary. But we should be careful that fourth years don't provide cheap labour for out-of-hours service rather doing it for educational and development reasons.'
