DES MOINES, Iowa (AP) — A round of elections in Iowa this month will ask some public sector workers whether they want to keep their unions or dismantle them. The elections are scheduled over a two-week period beginning Tuesday. They will be one of the biggest tests of labor strength in Iowa since a new law eliminated many collective bargaining rights for most public sector employees.

The law includes a provision requiring workers to vote periodically on their union representation. It counts non-participants as votes against the union. Union leaders argue the elections and the law aim to weaken workers’ rights. The president of the largest public workers union also says he’s concerned about the logistics of the elections, which will be held online and by phone.

The head of the agency overseeing the elections says the process will be efficient, fair and transparent.