Labour has contacted the police with information about UK mainland companies potentially involved in the illegal horse meat trade, amid accusations the government has fallen asleep on the job.
Shadow food secretary Mary Creagh said she had written to Owen Paterson, her government counterpart, to inform him of the letter.
The scandal around horse meat in beef products is threatening to engulf the government , as critics grew increasingly angry at the absence of action in Westminster
Ministers at the Department for the Environment, Food and Rural Affairs (Defra) consistently failed to put themselves forward for media appearances, leaving a vacuum of information as ever-more beef products were found to contain horse meat.
Downing Street said the developments were "distasteful" but it could not rule out horse meat being served to millions of school pupils and hospital patients.
"The Irish government has called in the police and fraud experts to investigate the horse meat fraud, yet complacent British ministers have not and are asleep on the job," Creagh said.
Asked if she would eat processed food labelled as containing beef, she said: "I certainly wouldn't, but I'm waiting for the government, the experts, the scientists, to tell us and issue proper clear advice for consumers.
"It's simply not good enough for ministers to sit at their desks and pretend this isn't happening."
The prime minister's spokesman was also asked if David Cameron would eat processed beef products.
"I haven't asked the prime minister myself. Our advice is to follow advice of FSA [Food standards Agency]," he said.
Speaking after the EU budget negotiations later, he said: "The FSA says there's no reason to believe any frozen food currently on sale is a danger to health."
The FSA has ordered UK retailers to test all processed beef products after beef lasagne from Findus was found to contain 100% horse meat.
The company has withdrawn 180,000 of the ready meals. The FSA said it was "highly likely" contamination arose from criminal activity.
Downing Street said the prime minister had "full confidence" in the food secretary this morning.