Thanks Walter for the response and interesting query. Unfortunately my reply is only based on perception so may not stand up to scrutiny. The UK is full of contradictions and division, perhaps particularly as far as agriculture is concerned. I suspect our histories have had a greater impact than is usually recognised.
Firstly, the UK has been a net importer of food for a long time supported by exports in other sectors. Our first foray into protectionism came in 1815 to protect against cheap grain imports from the US and Canada. This was dismantled when it became apparent that the price of food was politically more important than supporting production and we have remained importers since then with support in various forms periodically returning (particularly following the agricultural recession in the 1930s with the formation of monopoly marketing bodies). Ironically our self-sufficiency reached a 100 year peak when we first joined the EU because i) technology increased production more quickly than population growth ii) EU prices were high as a result of tariffs. export subsidy and intervention buying.
The impact of support has not been as simple as you might expect. There has been stress in the UK agricultural industry and our solution has been to increase farm size combined with the marketing boards in the 1930s. While (I would argue) as a result of better soil types, higher population density and a more entrepreneurial outlook (reinforced by demonstrable success) the Netherlands has intensified production on smaller units and improved on farm entrepreneurship. Ironically the disadvantage of scale forced collaboration on Netherlands farmers. I think I am correct in saying that the Netherlands had the only agricultural sector that was not reliant on subsidy. It is certainly the second biggest exporter of food and drink in the world by value. I worked for a period in the area adjacent to London and found that on the poorer soils most farming families took over farms in the 1930s from poorer areas of the UK while those on the better soils survived
The consequence for the UK is that
- Development through scale did not encourage technical innovation at farm level (it did require other skills in terms of capital accumulation and innovation in support industries was high - for example the UK was at one point a leader in GM technology)
- Protection through marketing boards also secured a livelihood without entrepreneurial input at farm LEVEL. (The EU maintained something similar)
- Large scale meant that collaboration was not historically necessary (but is now) (and meant subsidy per farm even recently was very high - politically the UK fought against descriminating in favour of small farms))
- The contribution of farming to the economy in the UK is small
- We have had no history of self sufficiency. While food was short and there was rationing in WW2, we did not have the starvation that much of Europe experienced.
- Nationally agricultural protection from imports is easy to sacrifice in exchange for access for financial services and historically industria;l access
Food nationalism here started with various environmental NGOs. This was for a number of reasons but in part due to the threat of (perceived) lower standards. There was a belief that EU standards were universally better and we would lose this protection. EU standards are high in some areas such as antibiotic use (thank you Sweden) and animal welfare (although I would add that as a non-farming nation the UK would (and has on occasion) adopted higher animal welfare standards than the EU). However, some of our pesticide MRLs are higher (ie. a lower standard) than the Codex or permitted in the USA and in at least some sectors EU greenhouse gas levels are higher than for other producers.
NGO nationalism was quickly followed by support from the farming industry.
I am not sure that most of the UK population felt particularly strongly about it although I suspect there was more support amongst (what we refer to) as the chattering classes.
I should perhaps research properly and write a paper!