As post-Brexit trade talks entered their final stages, fishing once again emerged as the main obstacle to a deal.

– Why is fishing important?

The issue has a symbolic importance in both the UK and in the EU that far outweighs its value measured in simple economic terms.

According to the House of Commons library, in 2019 the fishing and aquaculture industry contributed £446 million to the UK economy in terms of gross value added (GVA) – a measure of economic activity – which is just 0.02% of the UK’s total GVA across all sectors.

The total number of fishers on UK registered boats was around 12,000 in 2019, according to a House of Commons Library briefing.

– If it is such a small part of the economy, why is it holding up a trade deal with the EU?

While it is small overall, it is highly concentrated around fishing ports, meaning any impact on the sector will be sharply felt in those areas – a situation which is mirrored on the continent, where fishing is also a politically sensitive issue.

In the UK, the decision to join the then European Economic Community in 1973 has been blamed for the decline of the industry, with shared access to waters leading to competition from continental vessels.

The totemic status of fishing to Brexit supporters saw Nigel Farage and a flotilla of trawlers sail to London during the referendum for what became dubbed The Battle of the Thames as rival Remain-supporting boats also took to the river.

– Why have negotiations proved so difficult?

Fisheries policy is incredibly complicated, with limits set by the EU for how much of a stock can be caught – the total allowable catch – which is then divided between into quotas for the countries with fishing interests.

As the UK’s fishing grounds are so important for the EU’s vessels, there are concerns in the bloc’s coastal states about the loss of the resource and they have consequently fought hard to maintain access.

The negotiators in Brussels have been haggling over how much access EU boats will continue to have to British waters, what they can catch and for how long the arrangements will last.

On the other side, access to the EU’s valuable market is important for British vessels.