Around a third have also barred consultant-to-consultant referrals, forcing GPs to re-refer patients rather than allowing them to be referred between hospital departments.
GP leaders hit out at hospitals increasingly dumping work on GPs. They warned hospitals were forcing practices to issue prescriptions for medicines requested by hospital doctors and expecting practices to handle an increasing share of work involved with patients discharged from hospital.
In some cases, GPs reported that patients sent back to their GPs said they had not been notified of a hospital appointment. Poor communication with patients by hospitals was also driving up GP consultations with confused patients, GP leaders warned.
Out of the 51 PCTs who responded to the GP investigation, 15 said that if a patient did not attend a hospital appointment they would be referred back to their GP.
Three out of 51 did not allow consultant-to-consultant referrals and nine only allowed them in specific circumstances. Far more hospitals may operate similar policies. Many PCTs said hospitals developed their own policies on this area.
Londonwide LMCs chief executive Dr Michelle Drage described hospitals referring back to GPs as a 'massive issue'.
Dr Drage said the practice was 'symptomatic of a load of patient-unfriendly issues'.
'It goes to show just how un-customer facing hospitals are,' she said. 'All the focus is on us as GPs to be patient-focused.'
Hospitals are blanket-referring patients back to their GP, without providing any contact information for the hospital department, she said.
'Hospitals should be encouraging people to come in. They should be offering choice and offer patients a direct point of contact with the hospital,' Dr Drage said.
She added that asking GPs to prescribe medicines recommended by a hospital doctor was a waste of time. 'There is not an earthly reason why a hospital can't issue a drug,' Dr Drage said.
In a Londonwide LMC update last week Dr Drage warned that efforts to find savings in the NHS were unfairly focused on GPs, and called for pressure on hospitals to 'control the demand they place on our services'.
GPC deputy chairman Dr Richard Vautrey said referrals back to GPs were 'primarily about waiting list targets'.
He said they were increasing GP workload and needed to be addressed. Patients should be advised to tell the hospital if they could not attend, he said.
Hertfordshire GP Dr Mike Ingram said: 'I see lots of patients who say they haven't received notification of the appointment, or the notification was sent to the wrong address.'
Dr Ingram said it was unacceptable that poor organisation in hospital, rather than patients failing to turn up, led to GPs being forced to re-refer.