Environment Secretary Owen Paterson is to hold a horse meat summit with the Food Standards Agency (FSA) and retailers - after it emerged Findus beef lasagnes may have been contaminated since August.
The frozen food company reiterated its apology as the FSA ordered firms to carry out tests on all processed beef foods.
Findus UK confirmed it carried out a full product recall on Monday, two days before DNA tests found that some of its lasagnes contained up to 100% horse meat.
The Trading Standards Institute said the discovery of such high levels of horse meat suggested "deliberate fraudulent activity".
Prime Minister David Cameron said it was a "very shocking story, it's completely unacceptable" as Scotland Yard said officers had met with the FSA over the scandal. The force added that there is currently no official police investigation.
And supermarket Aldi said tests on its Today's Special frozen beef lasagne and Today's Special frozen spaghetti bolognese, which are produced by the same French supplier, Comigel, were found to contain between 30% and 100% horse meat.
Politicians and food safety experts played down the risk to human health, with Mr Cameron, speaking in Brussels, saying it was not about food safety but accurate food labelling and the industry would have to work hard to restore confidence.
"People will be very angry to find out they have been eating horse when they thought they were eating beef," he said.
Mr Paterson will meet with heads of food retailers and suppliers on Saturday at the Department for Environment, Food and Rural Affairs in London, a spokesman said.
Speaking to BBC News, the Environment Secretary said he had "great confidence" in the British food industry but urged consumers to return the affected lasagnes to retailers. "It is wholly improper that the public are presented with a product marked beef when it contains a significant amount of horse," he said. Asked whether he would eat the recalled Findus lasagnes, Mr Paterson replied: "Personally I would yes, because what we have in these cases, and the FSA has been quite clear, is shocking cases of mislabelling but there is no material that has so far been divulged which poses any threat to health."