David Cameron said he was "shocked" about the horsemeat scandal and understood why people were angry.
Taking the podium in Brussels, where the Prime Minister is attending the EU budget summit and was asked about the issue, he said: "This is a very shocking story.
"People will be very angry to find out they have been eating horse when they thought they were eating beef. I think it's very important we get this right. But it's not about food safety, it's about proper food labelling. The food standards agency should do everything they can to achieve this."
A leading food scientist says the rule change that sparked the horsemeat beef scandal affected lamb products too, and they should be tested.
Retailers and the Food Standards Agency held an emergency meeting today to decide how to proceed with the horsemeat scandal.
The government has called an emergency meeting with retailers and the Food Standards Agency to discuss the horsemeat scandal.