Dr David Bailey, GPC Wales chairman, said that since the GMS contract came into operation in 2004, 'it is difficult to justify a half-day closure'.
He said the recommendations were 'political issues' and GPs should consider services from a patient's viewpoint to ensure practices are responsive to their needs and expectations.
'If GPs and practices do not make themselves available and ensure access to services, governments may alter regulations to ensure practices comply with a more rigid GMS contract in the future,' Dr Bailey said.
But Dr Heather Evans, medical secretary at Dyfed Powys LMC, said the advice may undermine small practices.
'If small practices comply with the paper then we will have to pay staff to run the surgery and pay a dispenser as well. This is not in the global sum and at time of facing cuts to the practice this will cause us a lot of anxiety,' she said.
Dr Greg Graham, medical secretary at Gwent LMC, said there was already evidence that general practice is offering 'excellent access to patients' across Wales.
'I have no doubt that the revised patient satisfaction survey to be released next month will demonstrate this,' he said.