GPs have labelled a federal government crackdown on Medicare rorting as "intimidating" and "heavy-handed" for unjustly targeting doctors for treating their patients' mental and physical health problems together.

The Department of Health has sent a warning letter to 341 doctors who had the highest rates of co-claiming a mental health treatment plan alongside a standard consultation for the same patient on the same day.

341 GPs received the warning letter for co-claiming mental health treatment plan Medicare items. Credit:iStock

These doctors made co-claims for over 50 per cent of all their mental health consultations. The average co-claiming rate is 23 per cent, according to the department.

The GPs were asked to justify these claims or pay them back, warning the department may take compliance action, conduct audits and take legal action if a doctor was found to have breached Medicare Benefits Schedule (MBS) requirements.