"Ill thought out" NHS Urgent Care Centres (UCCs) could be putting patients at risk by diverting serious cases from A&E departments, according to experts.
The College of Emergency Medicine expressed "serious concerns" about the centres, saying they had been imposed for financial reasons.
It said they were were "ill thought out" and warned there was "no evidence of the clinical or financial benefits" of UCCs. It even believes patients could have their choices limited by not being able to attend A&E.
Ministers from the Department of Health believe the centres have an "important role" to play in providing emergency care for noncritical patients.
PCTs in England and Wales have said UCCs would be useful in reducing the pressure on A&E by treating patients who should be more appropriately seen by GPs and nurses.
Dr John Heyworth, incoming president of the college, said UCCs were being introduced on the assumption that most patients who attend A&E do not require emergency care.
He said there could be risks to patients who attend UCCs rather than emergency departments.
The college also urged the government to address "serious workforce shortages". It said the number of consultants working in emergency medicine should be more than doubled from 740 to 1,500 by 2012.