The senior doctor's union's criticising Health New Zealand's decision to call in the Employment Relations Authority to sort pay talks

Around 6000 doctors and dentists are walking off the job nationwide tomorrow and Wednesday.

The ERA's been requested to fix the terms and conditions of a collective agreement - in a move unprecedented for the public sector.

Association of Salaried Medical Specialists Executive Director Sarah Dalton says they've done some work with the ERA in the past.

She says they weren't happy with the way the ERA applied itself to the task and alleges there was a lack of independence.