Canada Post says it expects to have a backlog of mail in its major centres caused by the recent lockout of employees cleared by the end of the week.

John Caines, a spokesman for the Crown corporation, told CBCNews.ca the system dealt with a record volume of 70 million pieces over the weekend — about three times the normal volume — in a drive to deal with the backlog.

Last week, Canada Post stopped collecting letters from large circulation corporate clients  in an effort to slow the influx of mail into their already strained system.

All mail being brought into the corporation is now being accepted again, domestically and internationally, Caines said.

P.O.V.

Your Comments on Canada Post's pleas for patience:

"There's a backlog but they have no problem delivering complete junk mail to my house. I haven't gotten one bill or one of the five magazine subscriptions my family has yet." -- DBT1979

"It doesn't matter why it's delayed. JUST GET IT DONE!" -- NorthernThunder

Read more comments in our Community blog.

Caines also again appealed to customers for patience as Canada Post works through the backlog, saying the volume in centres like Montreal and Toronto is still "very, very heavy."

"Our major plants are still very full," Caines said Tuesday. "All of the plants have an excess, but we hope to have it cleared out by the end of the week."

The Canadian Union of Postal Workers has accused Canada Post of refusing to pay its workers the overtime needed to alleviate pressure on the system.

Irwin Nanda, CUPW's national director for the Toronto region, said he's heard from several members in and around the city who report mail piling up.

"Carriers came into a lot more mail than they would normally see on Monday when the plant's not running full-tilt," he said of the weekend sorting push.

"If they haven't finished their route in the eight hours, they have to bring that mail back."

Canada Post's Caines said carriers are authorized for one hour of overtime at the beginning of their shifts to give them more time for sorting, as well as some en route overtime as needed. Casual workers have also been brought in to work in major centres, he added.

But Nanda called for Canada Post to bring in a "clean-floor policy" for overtime for all carriers, not just the sorters, to clear the backlog in a day.

"The one hour just won't cut it," he said.

Postal workers across the country were locked out June 14, after 12 days of rotating strikes.

Canada Post workers were legislated back to work by the federal government after its bill imposing a new contract on them received royal assent on June 26.

The government said it was necessary to get Canada Post working again to protect the country's recovering economy.

The Opposition NDP led a lengthy filibuster, arguing the bill trampled the postal workers' right to collective bargaining.