The impact of Brexit on the UK's agri-food industry on a post-Brexit situation where, he says, no plan exists is deeply troubling a leading UK academic has said.

Professor Tim Lang, City University, told BBC4 radio this weekend that Brexit will have an "enormous impact on the food system".

The CAP, he said, is far from perfect, but it has helped keep food prices relatively stable. He was also deeply concerned in advance of the vote that food was not centre to the debate. "Food was one of the main reasons behind the common market place."

He reminded British consumers that 30% of fruit comes from the EU and this is something they now need to think about, while 16% comes from the rest of the world, with just 54% home grown.

Food prices are highly likely to go up as the pound will go down, and imports will cost more."

While the long-term plan, he said, may be to grow more food in the UK, he questioned who would actually grow it, in a country that country is heavily reliant on foreign labour to grow and process it in factories.

"Those who voted for Brexit - are they now prepared to pick brussels sprouts and cabbages? I don’t see any sign of them wanting to do that. It's Eastern Europeans who are prepared to do this (work)."

Ian Wright, Director of the Food and Drink Federation, which represents over 6,000 UK businesses, said Brexit is the biggest peace time challenge the UK has faced. He said a return to WTO tariffs are far, far less advantageous than current tariffs, while he also pointed to a huge reliance on foreign workers in the food and drink industry in the UK.

Of the UK's Food and Drink Federation membership, 10% were pro leave and 70% backed remaining. The immediate shock, he said, was watching as costs went up by the second as the pound fell.

David Thompson of the Scottish Food and Drink Federation, told the radio programme that the immediate reaction was 'confusion and uncertainty' and that turned to anxiety for those who campaigned hard to remain - the Scottish Distillers.

Scottish whisky is the UK's biggest food export, so is Scotland's biggest food export too, he said, and Europe is its biggest market.

However, Scottish fishermen were happy with the Brexit vote. One told the programme that it was a "totally new ball game". One emotional fisherman was emotional as he talked about how Europeans had stole their fish.

The food industry in the UK is the biggest manufacturing sector, with £29bn of exports at stake.

Managing Editor with the Grocer magazine in the UK, Julia Glotz, told the programme that the price of some raw materials surged overnight for some smaller manufacturers and they are worried about the impact in the longer term.

A West Wales pig farmer told the show what while the majority of Wales voted to lead, he voted to stay.

The area around him is classed as an objective 1 area, as one of the poorest parts of the EU so funding has been good.

Tim Worstall, a Senior Fellow at the Adam Smith Institute (a free market think tank), told Dan Saladino on the programme that things will settle down after a month or two food will become more affordable.

The former speech writer for Nigel Farage said people really don’t understand how the markets work. "We don’t buy food from the European continent because we are members of the EU. We buy from a French farmer who sells to a UK supermarket chain and why would that change?

We get to decide what our import tarrifs are – why would we make things that we want to buy more expensive? If we like continental food, we won’t put tarrifs on it."

He also said that UK farmers should be buying high-value food stuffs, but not food products such as turnips when it can import cheaper.

UK farmers, he said, should be looking to the New Zealand farm model, which has no subsidies.

Dave Harrison of Beef and Lamb New Zealand said the country turned its agricultural industry around when subsidies ended.

Tim Lang also said it was an exciting time for food democracy in the UK, with a renaissance over the past 30 years in food thinking and experimentation.

"There is an opportunity, with a wide open gap for progressive food movements to come forward and say 'we want a good food system for Britain' and if the political classes cannot deliver that, we have to push it onto them."