Proper government investment in trading standards and meat hygiene services could have meant the horsemeat "burger scandal" was picked up without relying on the Irish authorities, Unison said today.
It said swingeing budget cuts have severely limited the ability of officers to protect the public and curtailed services - and warned against watering down EU meat inspections.
Processing firm Silvercrest Foods blamed European suppliers today.
Beef products testing positive for horse and pork DNA were produced by Liffey Meats and Silvercrest in Ireland and one British plant, Dalepak Hambleton.
Silvercrest, a subsidiary of ABP Foods, said it had removed the offending lines from sale after the Food Safety Authority of Ireland (FSAI) found that some frozen beefburgers contained the DNA.
A spokesman said: "Although the products pose no risk to public health, Silvercrest has taken immediate action. Silvercrest has never purchased or traded in equine product."
It said it had launched a full-scale investigation into two continental European third-party suppliers who are the suspected source of the product.
The FSAI found low levels of horse in beef products sold in Tesco, Lidl, Aldi, Iceland and Dunnes Stores. They were all taking action today.
One sample, Tesco Everyday Value Beef Burgers, showed about 29 per cent horse meat relative to beef content.
It is illegal not to declare every ingredient on product labels and concerns were raised today that practising Jews and Muslims may have inadvertently eaten pork, as well as concerns about the lack of traceability.
Britain exports horse meat to Belgium, France and Italy.