As public-health authorities investigate a new meat recall over fears of listeria contamination, federal food inspectors say they're still not adequately funded to keep up with plant inspections.

The latest recall involves packaged meats from Siena Foods' Inc. Listeria from the meat is being blamed for sickening two people who were sent to hospital back in December. Both have since recovered.

The recalled meats include Siena brand Coppa and Siena brand Prosciuttini, with best before dates between June 20 and June 22. All have tested positive for listeria.

As the investigation continues, the union representing food inspectors is noting there are significant gaps between Canadian and U.S. food safety regimes.

The union says increased demands from U.S. food safety regulators are adding further stress to already overworked inspectors.

They say that because of new demands from the U.S. Department of Agriculture, plants that package meat for the U.S. market are being checked at least daily, if not more often, while plants that produce for Canada's domestic market are inspected just once a week.

The CFIA has been forced to increase its presence at dozens of meat-processing plants that ship to the U.S., after USDA auditors complained that inspections were too infrequent to meet their standards.

The ramped-up inspection cycle not requires at least one visit for every 12 hours of production. That new policy was instituted last November, so operators in Canada could continue to export their products to the United States. (Some of these plants are also authorized to distribute their products across the country.)

The union that represents inspectors, the Agriculture Union, says that in order to keep up with U.S., the CFIA has resorted to paying for more overtime inspections, because it is unable to hire new inspectors.

On Monday, the inspectors released the text of an internal staff memo, which says "the CFIA will be providing additional inspection coverage… to better meet the USDA's technical requirements for products exported to the U.S."

The union's president Bob Kingston says the current system is unsustainable. He says up to 50 additional meat inspectors will be needed long-term to meet the new USDA requirements.

"Unless the government makes new investments in food safety, the CFIA will face a choice: ignore the USDA's demands and risk losing access to the U.S. market for Canadian processed meat products, or elevate food contamination risks for Canadian consumers by diverting scarce resources away from other inspection programs," Kingston said in a news release issued by the union.

The union notes that in September, 2009, Agriculture Minister Gerry Ritz promised an additional $75 million for food safety, including 170 new meat inspectors. Those promises were made in response to the Weatherill Report on the Maple Leaf Foods listeria outbreak, which killed 22 people.

But the union notes that those new inspectors were promised before these new USDA requirements were made. Kingston says even if the promised new inspectors arrive, they won't be enough, since they are being offset by attrition.

"The CFIA has told us they're on target for bringing on 30 news ones this spring. According to our folks in the field, that will hardly fill the gap caused simply by attrition," he told CTV News Channel Monday.