Staffing decisions by Canada Post are delaying the mail, B.C. letter carriers say. (CBC)

Staffing decisions by Canada Post have resulted in unacceptable delays in mail delivery, the union representing letter carriers in British Columbia says.

Canada Post hasn't been backfilling employees who become ill or take leave, Ken Mooney of the Canadian Union of Postal Workers told CBC News.

"The non-delivery has a ramification on the community, of course, because people depend on GST cheques and family allowance cheques and various other correspondence, and they depend on Canada Post for that service," Mooney said.

Canada Post says unplanned absences of workers pose a challenge, but if a cheque is in the mail it will get through.

"Definitely if there are important items like that, we're getting them out," said spokeswoman Colleen Frick. "We're taking the necessary measures to make sure that customer service is not jeopardized for important mail."

However, the union says it has a growing list of grievances that suggest Canada Post has not been covering routes adequately and in fact has a policy of non-delivery.

Canada Post says there is no non-delivery policy. However, with the growing use of email, the overall volume of mail has dropped and the Crown corporation is trying to adjust the number of hours worked accordingly.

"From where the item is coming from there is either a two-, three- or four-day delivery standard, and we're meeting that 96 per cent of the time — either meeting or exceeding that number," Frick said.

The union's Mooney says delayed delivery is more than an inconvenience. "Well, in fact, the Canada Post [Corporation] Act states — and it's an act of legislation — that if you intentionally delay mail it may be an indictable offence resulting in up to five years of imprisonment."