Junior hospital doctors say they are prepared to strike if necessary to 'defend' the public health system they work in.
The union for the doctors is in a stalemate with district health boards over a new collective employment contract governing pay and conditions.
DHBs have proposed changes to the contract, which has led the Resident Doctors Association to spend what it says is 'tens of thousands' of dollars on a television advertising campaign.
National president Curtis Walker says the union has a mandate from its members for strike action, but has not issued a notice to that effect yet.
However, DHBs accuse the doctors of mischief, saying the advertising campaign on television is an example of 'fiddling while Rome burns'.
The campaign was launched over the weekend.
DHB industrial relations spokesperson Karen Roach says the boards believe the TV campaign shows the doctors had no intention of turning up for last week's bargaining talks and have taken the chance to create mischief.