The indicator offers a single quality point - worth £124 to an average practice - for recording the ethnicity of all new patients. But GPs want it expanded to cover all patients and called for more points.
City and Hackney LMC chairman Dr Kambiz Boomla said: 'This will not deal with the backlog of people who are uncoded.
'Even in areas of high turnover like east London, 70 per cent of patients are permanent.
'Only monitoring ethnicity on new patients means it will take years to create a full list.'
Bradford GP Dr Brian Karet agreed: 'Only recording ethnicity for new patients is a sop.'
In most areas, list turnover was no more than 5 to 7 per cent per year, he said. 'On that basis it would take about 20 years to get a full list.'
Dr Boomla said that partial recording of patients' ethnicity would mean it was impossible to draw any conclusions from the data, or use it to address health inequalities.
'In east London we have large numbers of patients with diabetes, especially in the South Asian population,' he said. 'Is control of diabetes worse in this group, or just the same?'
Preliminary findings from research Dr Boomla is carrying out show South Asian people with high cholesterol are more likely to be put on statins than black people. It was important to have data on the ethnicity of all patients so its effect on different diseases and their treatment could be investigated, he said.
'We have to be sure we are mapping inequalities in health and addressing them - if we don't, the NHS is open to the accusation that we are not providing healthcare equitably,' he said.
However, GPC deputy chairman Dr Laurence Buckman said many GPs were opposed to the collection of such data because they fear it could be 'racially divisive'. He added that the DoH would not have been prepared to fund the collection of data on all patients because this would require 'a colossal hike in funds'.
Dr Buckman said that if in future it became clear that most GPs favoured collection of ethnicity data for all patients, the GPC would consider arguing for a directed enhanced service.