Prime Minister Bill English is expected to make another pre-Budget announcement at a party conference protesters are targeting.
The Public Service Association (PSA) says it'll set up 200 cut-outs of qualified ambulance professionals and health workers "missing due to underfunding" outside the National Party Northern Regional Convention at the Waipuna Hotel and Conference Centre on Sunday.
The union expects Mr English to make a pre-Budget announcement about funding for medically unqualified ambulance assistants to work with a qualified ambulance officer who are otherwise working on their own.
The union wants two medically qualified officers in every ambulance, known as double crewing.
Welfare activists also say they'll be outside the convention.
Auckland Action Against Poverty says unemployed people need a living income and access to state housing, and on Mother's Day it will "acknowledge sole mothers who face economic punishment from Work and Income".