Canada Post says it cannot make good on its holiday delivery guarantee.
Officials tell CTV Ottawa that 5 weeks of rotating strikes by unionized postal workers have caused major backlogs within the mail system.
They're dealing with volumes that are triple that of a normal holiday season.
The federal government passed back-to-work legislation last week.
Canada Post says adding to the delays are 'illegal' protests in places like Ottawa, Toronto, and London.
The union that represents postal workers calls the situation "a manufactured crisis."