Frustrated teachers, firefighters, health and other public workers are walking off the job over three days to protest a "contemptuous" government wages offer.
Stop-work action forced schools to open several hours late in northwest Tasmania on Tuesday, with further disruptive rallies planned in Launceston on Wednesday and in Hobart on Thursday.
Unions rejected the state government's offer of a one-off three per cent pay rise while longer-term deals are negotiated.
Hundreds of workers rallied at Burnie and Devonport in what Health and Community Services Union secretary Robbie Moore said was evidence of unprecedented anger.
Ramped-up industrial action that could impact government income was also on the cards, he said.
"I've been involved in the health industry for over 20 years," Mr Moore said.
"I've never seen a situation like this where the workers feel like there is absolute contempt from the government."
Business, Industry and Resources Minister Felix Ellis said the three per cent offer was fair and includes additional conditions around leave and entitlements.
"We're disappointed that strike action is being taken ... particularly when it comes to the school strikes, because every school day matters," he told reporters.
Australian Education Union state manager Brian Wightman said the decision to close schools was avoidable and made by the government.
"Educators are fighting for safer schools and more teaching and learning resources to benefit students," he said. "We thank parents and carers for the incredible support they have shown our teachers."
The government's offer was generic and did not include specific claims, such as addressing paramedic overtime and staffing levels, Mr Moore said.
The government plans to cut 2500 public sector jobs to help balance the budget, with state debt forecast to reach $13 billion by 2027/28.
Politicians will receive a 22 per cent pay increase, after seven years of a pay freeze, even though the state government tried to block the rise in parliament.
The government was unable to afford the unions' claim of 21.5 per cent over three years, Premier Jeremy Rockliff recently said.
