In short, no. Once a union has been certified, the union holds representation rights. Mechanisms exist under the relevant labour relations act for employees to seek decertification of a union, but only where decertification is not employer-sponsored.
Where an employer shuts down the business, only to start up again under some other identity, or where key employees of the former business open up a new business, the union may make a related employer/sale of business application to the labour relations board. If the union is successful, even the most sophisticated attempts to avoid unionization will be defeated.
Given the very serious consequences of union certification for a business, employers should seek legal counsel immediately where they believe that a union may be initiating an organizing campaign.