Doctors have a duty to help ensure migrants pay for NHS care, say No 10 Downing Street says there is an obligation on GPs to ensure the taxpayer gets a good deal from the health service.
Downing Street has said family doctors have a duty to make sure foreign visitors are fairly paying towards the cost of their NHS care, despite warnings against turning GPs into border guards.
Doctors have raised concerns that they will be forced to make decisions about the immigration status of their patients, after the government said it wanted to raise £500m from foreign visitors to help pay for the cost of their medical care.
The prime minister's spokesman argued there was an obligation on doctors, like all public sector workers, to ensure the taxpayer got a good deal from the health service.
Asked about the role of GPs in enforcing the new rules, he said: "There is a real duty that taxpayers will expect us all to have to play our part in ensuring fairness for those who fund the NHS."
Downing Street's intervention came after Frank Field, a former Labour welfare minister, strongly criticised GPs who are resisting the coalition's efforts to make temporary migrants pay more.
He said this stance "exposes the gap between what doctors expect in salaries and how far they are prepared to go to meet their duties as citizens".
"No one is asking GPs to be part of the border agency but they do have a duty to their patients, who pay their salaries and all NHS bills, to ensure that those drawing health services have paid their way," Field said.
"That's the overwhelming view of their patients, who are increasingly fed up with a welfare state that rewards something for nothing rather than affirming the something for something principle."
The Department of Health has presented a new analysis suggesting temporary migrants are costing the NHS up to £2bn a year, and argued this could be reduced by a quarter through a charge on new arrivals, better enforcement of the current rules and discouraging people from abusing the system.
However, doctors' groups are deeply concerned that the proposals will force them to make difficult assessments about their patients' right to be in the UK and could get them caught up in legal difficulties.
Dr Clare Gerada, chair of the Royal College of GPs, said family doctors "must not be the Border Agency", and suggested the proposals demonstrated xenophobia. "We are yet again denigrating immigrants who are more likely to more likely to be caring for us than abusing our health system," she said.
Others have questioned the government's figures. Dr Chaand Nagpaul, chair of the British Medical Association's GP committee, said there was "limited evidence to suggest that migrants or short-term visitors are consuming large parts of the NHS budget".
In the House of Commons the health secretary, Jeremy Hunt, denied that the policy discriminated unfairly against immigrants. "Far from being xenophobic, as some on the opposition benches have said, this government thinks it is right," he said.
Andy Burnham, the shadow health secretary, suggested the government was using the issue as a smokescreen to distract from its failing record on accident and emergency care. "We've got used to his style. Everything is always someone else's fault … now it's immigration to blame," he told MPs.
"But there's an inconvenient truth that gets clearer day by day and he can't spin this away: A&E is getting worse and worse and worse on his watch … the NHS stands on the brink of a dangerous winter." The Guardian