WINNIPEG -- A backlog in shipping means some gifts might not make it under the tree in time for Christmas.

The holiday season is the busiest time for postal services and the pandemic isn't helping.

The Winnipeg chapter of the Canadian Union of Postal Workers said mail service has been at a Christmas level volume since May.

Attributing it to an increase in online shopping amid COVID-19, it's creating a stressful time for the mail service.

"We have workers who are working up to twelve-hour shifts coming in for their eight-hour shift and working another four of overtime," said Cameron Fortier, vice president of the Winnipeg union.

Fortier said as of the most recent count, there are 148 trailers of mail in Winnipeg that need sorting.

"To support that level of delivery, our processing plants have been running at capacity around the clock. We are doing everything possible to deliver the surge of holiday items while maintaining important safety measures designed to keep employees and customers safe during COVID-19," said a Canada Post spokesperson in an email to CTV News.

Paul Larson, a supply chain management professor at the University of Manitoba, said the only way to solve the problem is to find more capacity or wait for the demand to drop.

"It's a classic balance of capacity and demand. Suddenly we are thrust in a situation where demand is exceeding capacity, at least in the short run, so then there is this scramble," he said.

As capacity is too low for the high influx of packages, Manitobans are left waiting.

Kevin Oestreicher lives about an hour south of Winkler, Man. He told CTV News he still needs three of the eight presents for his kids.

Though two of his four kids will be missing some gifts, the holiday is far from ruined.

“We have food and a roof, but most importantly, we have each other,” said Oestreicher

Amy Scott said the Lego Batman set for her 11-year-old son has been stuck in transit since Dec. 11.

Kuki Kuklica's present for her husband didn't arrive. She said she'll have to wrap a picture of the present to make do.

These are a few of the dozens of stories CTV News received about Manitobans waiting for parcels after putting out a call on Facebook.

Fortier said he understands the frustration and says postal workers will get through this like they always do.

"Be patient with us, we are working throughout this the best we can," he said.