Shadow DEFRA secretary Mary Creagh has accused the government of failing to take action after beef lasagne made by Findus was found to contain up to 100% horsemeat.
The Food Standards Agency (FSA) has told food companies to carry out urgent tests on all beef products after tests showed frozen Findus lasagnes contained between 60 and 100% horsemeat.
Findus has withdrawn packs of its frozen beef lasagne ready meals, made with meat supplied by its French supplier Comigel, and apologised to customers.
The FSA warned consumers who have bought Findus Beef Lasagnes not to eat them and return them to shops amid fears they could contain traces of the equine drug phenylbutazone, or “bute”, which is harmful to humans.
Tesco has decided to withdraw its Everyday Value spaghetti bolognese, which is produced at the same site by Comigel.
“I’m very shocked at the latest news about 100% horsemeat being found in the Findus products,” Ms Creagh told BBC Radio 4’s Today programme.
“It’s vital that people, when they go shopping, have confidence in the food that they are buying – that it’s properly labelled, legal and safe for them to eat.”
Ms Creagh said the latest revelations were a “whole new step” in the horsemeat scandal and it was now clear there was “widespread criminal activity”.
“The Irish government called in the police on Monday or Tuesday of this week. My question is: why haven’t the UK government ministers done the same? I want ministers to explain what exactly is happening,” she said.
The FSA has admitted that meat from eight horses slaughtered in the UK last year tested positive for bute, a banned veterinary medicine which should not end up in the food chain.
Bute can cause rare cases of a serious blood disorder, aplastic anaemia.
Six horses had entered the human food chain – five in France and one in the UK – and the FSA has not been able to trace two animals.
Catherine Brown, chief executive of the FSA, described the situation as appalling and said it was likely criminal activity was to blame.
DEFRA secretary Owen Paterson called the situation “completely unacceptable” and vowed to take action.
The latest developments in the horsemeat scandal follow revelations this week that a consignment of meat containing 80% equine DNA was discovered in freezers at Freeza Meats in Newry, Northern Ireland.