The variety of trade export goods has dropped, with 1,645 fewer types of British products exported to every EU country.

The report does not include the service sector, which has performed better than many experts had expected since Brexit.

The authors said there was a “noticeable worsening of EU-UK trade in 2023”.

“The negative impacts of the [trade agreement] have intensified over time, with 2023 showing more pronounced trade declines than previous years,” the authors added.

Farmers, clothing makers, and wood and paper manufacturers have been among the hardest hit industries, with many sub-sectors’ EU export value falling by well-over half.

The biggest drop in export value was for edible fruit and nuts, which nosedived 73.5%.

Trade with smaller and more distant countries in the EU has been affected the most, while trade with larger and closer countries has been affected the least.

The authors said many smaller British producers had given up on exporting small amounts to some EU nations since the creation of many forms of post-Brexit trade red tape or non-tariff barriers.

Jun Du, one of the authors of the research, said increased rules and regulations, such as safety checks and labeling requirements, had contributed to the fall.

“While these measures do protect consumers, competition and the environment, they also increasingly bring difficulties and costs for traders,” she told the BBC’s Today programme.