The Canadian Food Inspection Agency says there was a delay in getting information from the Alberta meat packing plant at the centre of a massive beef recall.

CFIA president George Da Pont said Wednesday that inspectors asked XL Foods to provide more information about “critical points” where E. coli contamination might be present on Sept. 6., but did not get an immediate response.

That occurred two days after U.S. food inspectors found E. coli in a shipment of beef from XL Foods.

CTV News has learned that XL Foods delayed supplying testing results for meat produced during Aug. 24-28. Food safety inspectors also found the plant had poor sanitation and maintenance, and it did not have a monitoring system in place to deal with high E. coli rates.

Still, Da Pont told reporters in Calgary that an immediate beef recall wasn’t necessary at that point because “every bit” of potentially contaminated product was accounted for.

The recall was eventually issued on Sept. 16 and has been expanded several times since to include more than 1,500 products.

Also in Calgary Wednesday was Agriculture Minister Gerry Ritz, who said that XL Foods will remain closed until the head of the CFIA sends a written letter pledging that food products from the plant are safe.

XL's meat-processing plant in Brooks, Alta. is believed to be the source of the E. coli contamination that’s prompted the recall of 1,500 meat products so far. The CFIA temporarily suspended XL Foods' operating license last week, leaving more than 2,000 employees temporarily out of work.

The E. coli crisis prompted Prime Minister Stephen Harper to defend Canada’s food safety record in the House of Commons earlier Wednesday.

Harper said he “stands behind” the Canadian Food Inspection Agency, which decided to suspend the Alberta-based meat processing plant’s licence on Sept. 27, weeks after E. coli was first detected on beef shipped to the U.S.

“Notwithstanding that there are problems to which the agency must respond to from time to time, Canada’s food safety record is among the best in the entire world,” said Harper.

Interim Liberal Leader Bob Rae pointed out that Canada has a higher rate of E. coli contamination than both the U.S. and Europe, and asked why regulations regarding E. coli are not clearly set out in the law and enforced by the CFIA.

Harper responded: “These things are not determined by politicians, they are determined by the Canadian Food Inspection Agency.”

During an emergency debate on the matter in the House hours later, opposition parties wasted no time blasting the Conservative government’s handling of the beef recall.

"We have some of the finest inspectors in the world, but they are hamstrung by a lack of resources, leaving them incapable of performing necessary functions of their jobs,” Liberal MP Frank Valeriote said.

“Clearly we have seen that the industry, while it can work in partnership, can no longer be left to police itself."

Rae accused the government, and especially Ritz, of “cowardice” for not addressing the issue head-on.

Pierre Lemieux, the parliamentary secretary to Agriculture Minister Gerry Ritz, countered that the CFIA’s response to the E. coli problem was swift and effective.

"The Canadian Food Inspection Agency acted to contain contaminated products beginning on Sept. 4, and they've been acting ever since," he said.

Earlier, Ritz repeated the government’s message that 700 new CFIA food inspectors have been added in recent years -- 170 of them dedicated specifically to meat inspection. He said there were 46 CFIA staff members at the XL meat-processing plant in Brooks, Alta. prior to the E. coli discovery – including 40 inspectors and six veterinarians.

Last week, the United States banned all imports from XL and pulled the company’s beef from stores in 30 states, including Wal-Mart.

Meanwhile, the union representing federal food inspectors says it’s unaware of the hundreds of new positions the Government claims have been added to their ranks in recent years.

“There’s obviously a lot of politics going on,” Agriculture Union National President Bob Kingston told CTV’s Canada AM on Wednesday.

Kingston hopes a thorough investigation into the operations at XL Foods will be able to pinpoint the problem.

He said as higher volumes of meat are being processed through facilities like XL Foods, parts of the inspection process have been turned over to plant employees.

“There’s a lot higher volume and the ability for the number of inspectors who were there to keep up is compromised,” said Kingston. “Some of the responsibilities of the inspectors are shared with plant employees in a form of self-regulation.”

He said that over the years plant employees have taken on more of a carcass sanitation inspection role.

“Given where E. coli comes from, it’s fairly safe to guess that that was the part of the investigation where the problem lies.”

Meanwhile, the beef recall continues to expand with products being pulled from the shelves in each province and territory.

On Tuesday, the largest beef recall in Canadian history was expanded to include steaks, strip loins and sausages sold coast-to-coast, including unlabelled and unbranded beef products sold at a variety of retail stores.

Also Tuesday, health officials in Saskatchewan reported a spike in E. coli cases after recording 13 infections last month. The province normally records between zero and four cases in September.

Alberta Health Services also confirmed that it is investigating 10 different cases of people falling ill from E. coli.

Of those cases, five are linked to the E. coli outbreak from the XL Foods and involve meat purchased at an Edmonton Costco.

With files from The Canadian Press