More than 5000 doctors from 32 public hospitals have defied legal orders and begun a three-day strike — NSW doctors’ first industrial action since 1998.

The strike is cutting staffing to public holiday levels from Tuesday morning until 10pm on Thursday as part of a campaign for a 30% pay rise and a guarantee of 10-hour breaks between shifts.

Driven by the Australian Salaried Medical Officers’ Federation NSW (ASMOF NSW), the strike follows a nine-month negotiation between the union and the government that ground to a halt in February.

The NSW Industrial Relations Commission had ordered the union to stop organising any industrial action for three months and to delete any references to a strike from its social media and website.