The NHS website's quality mark, signalling accredited sources, will not appear next to EMIS Clinical Immediate Reference (ECIR) articles if the decision is confirmed.
The articles aim to provide GPs with up-to-date information on diseases and their management that can be accessed during consultations.
The NHS Evidence advisory committee's draft response said the processes used to produce ECIR articles met only 20 out of 25 accreditation criteria.
In particular, NHS Evidence said EMIS did not show that a monitoring and audit policy was in place. It also considered the way information was synthesised from primary to summary guidance was 'not adequately described', and how the strengths or weaknesses of evidence were evaluated was not clear.
Dr David Haslam, chairman of the NHS Evidence advisory committee, said: 'The draft decision is now going out for public consultation, and the decision will be reviewed by the committee in light of any feedback received before making a final recommendation.'
Dr Gordon Brooks, head of EMIS knowledge-based systems, said he was 'very surprised' at the draft decision, as EMIS had 'worked closely' with NHS Evidence.
'Our submission went to the final review panel meeting with a recommendation that it be passed,' he said. Dr Brooks added that EMIS will make further submissions and work to address outstanding criteria.
'The accreditation by NHS Evidence is an ongoing process,' he said. 'We expect to meet the outstanding criteria.'
EMIS is the second organisation to fail to get the quality mark. Earlier this year, GP reported that the British Thoracic Society failed to gain NHS Evidence accreditation (GP, 12 March).