The Health Minister isn't ruling out a law change affecting some doctors ability to strike

Tens of thousands of union members across health, education, and the public sector are walking off the job on Thursday.

Minister Simeon Brown was booed at a union conference yesterday, where he told the audience strikes were unethical.

Brown told RNZ the law might have to be considered if this continues, but he wants it resolved.

He says the law is clear around next steps, noting Health NZ's applied for terms to be fixed, and he'd sought voluntary arbitration.

But Brown says the union continues to pursue strike action.