Prime minister to warn exit from EU would cost farming industry £330m

David Cameron says without single market cost of exporting British beef will soar to 240m, with 90m added to lamb exports

The prime minister will warn that Britain's exit from Europe would harm lamb and beef farmers, costing them an extra 330m a year to export their goods.

"If we left this single market and, as some suggest, relied on World Trade Organisation rules, the extra costs of exporting British beef would be 240m a year. An extra 90m would be added to the cost of British lamb exports," he will say on Friday.