Dr Surendra Kumar, president of the British International Doctors Association, warned the rules will result in the 'exploitation' of overseas doctors.
'Somebody from abroad who hasn't got a foothold would be pressured to take any job under any condition just for the sake of security,' he said.
At present, salaried GPs are included on the list of 'shortage occupations', making it easier for GPs from outside the European Economic Area (EEA) to apply for work permits.
But the ratio of GPs to vacancies has increased in recent years. A statement from the Home Office Migration Advisory Committee last week made clear that GPs are to be removed from the list of shortage occupations.
'Tier 2' of the new immigration system, which deals with work permits for skilled roles, gives applicants bonus points if they are applying for jobs in hard-to-fill professions. The new rules will make it harder for practices to 'sponsor' overseas GPs to fill specific vacancies.
However, the system used for highly skilled migrants who do not have jobs lined up - 'Tier 1' - remains unchanged since its introduction in February.
A spokesman for the international department at the BMA said she 'would anticipate that more individuals will be able to access roles under Tier 1 than Tier 2'.
Dr Kumar said he believed the rules were a conscious strategy to put pressure on conditions across the profession: 'All these new Darzi centres will be able to employ people at much lower rates than they would be able to offer British doctors,' he said.
The BMA spokeswoman said that jobs for overseas doctors 'are becoming increasingly limited across the board'.
Comment below and tell us what you think