Canada Post has issued a 72-hour lockout notice to the Canadian Union of Postal Workers. It comes on the heels of the company’s statement that their latest offer to the union be considered final. A lockout could be put into effect as early as Friday.

The Crown corporation says the CUPW's demands are "not affordable" and would add $1 billion in costs over the contract term. “The uncertainty caused by the prolonged negotiations and the union’s strike mandate is having a negative and escalating impact on the postal service,” Canada Post said in a press release issued early Tuesday morning. 

The CUPW insists it has been showing up to the bargaining table with proposals to make the post office even more profitable and improve services for businesses and the public. The union also stated on Monday that it wanted to continue to work and would not file their 72-hour strike notice.

"We knew this was their game all along. They are sabotaging the public review of the post office. They refused to negotiate fairly with us and now they 're locking the doors and will try to starve us into submission," said Mike Palecek, president of the Canadian Union of Postal Workers, in a statement. 

With files from The Canadian Press