Gary Corbett, a veteran scientist at Natural Resources Canada, has been named acting head of the Professional Institute of the Public Service of Canada, the country's second-largest public service union.
The position became vacant when PIPSC president Michèle Demers died of a stroke earlier this month.
Corbett has served as steward, chairman and director at different levels of PIPSC, which represents professional employees in the federal government.
He takes over as president immediately and will remain in office until June 21.
Corbett has a master's degree in mining engineering from McGill University and has spent much of his scientific career studying the Cape Breton coal industry
A new president will be elected by June 17.