Image copyright Getty Images

Former Deputy Prime Minister Nick Clegg has warned that leaving the European single market would lead the UK "off a cliff towards higher food prices".

He said items like chocolate, cheese and wine would be hit by a "triple whammy" of tariff checks, customs checks and workforce shortages.

The comments come as the government works out what Brexit should mean for trade and movement of people.

Supporters of Brexit have accused Remain supporters of scaremongering.

Foreign Secretary, and prominent Leave campaigner, Boris Johnson predicted last week that the UK would get a trade deal "of greater value" with the European Union than it has currently as part of the single market.

He added that talk of "soft" Brexit - retaining some form of membership of the single market in exchange for some conceding of control over immigration - and "hard Brexit" - leaving the single market but having fuller control over migration - was purely "theoretical".

Mr Clegg, who is now the Lib Dems' spokesman on Europe, predicted that "hard Brexit" - automatically reverting to World Trade Organization trading rules - would affect UK consumers.

Last week, Tesco removed products made by Unilever - including Marmite, Comfort fabric conditioner, Hellmann's mayonnaise and Ben & Jerry's ice cream - from its website, after the manufacturer raised its prices, citing a fall in the value of the pound. The row was resolved, with the supermarket selling the items once more.

Mr Clegg said: "It's clear that Marmite was just the tip of the iceberg. A hard Brexit will lead us off a cliff edge towards higher food prices, with a triple whammy of punishing tariffs, customs checks and workforce shortages.

"The only way the government will be able to avoid this outcome is if it maintains Britain's membership of the single market."

A Lib Dem report says £11bn worth of agricultural products the UK sells to the EU each year would be hit with an average tariff of 22.3%.

Tariffs on beef exports would be set at 59%, chocolate at 38%, cheese at 40% and wine at 14%, it adds.