Hertfordshire scientists will be allowed to grow a genetically modified crop containing omega-3 fatty acids, the government has said.
The Department for Environment, Food and Rural Affairs (DEFRA) has given the go-ahead for field trials at Rothamsted Research Centre in Harpenden.
It means engineered plans grown in a laboratory can now be tested "under real life conditions".
The initial aim of the crop is to benefit the fish farming industry.
The trial, which is reportedly the first field trial of nutrient enriched crops in the UK, would see the fatty acids added to a crop of camelina plants.
Oily fish such as tuna, mackerel, and sardines do not produce omega-3 fatty acids naturally, but obtain them by consuming certain types of marine algae.
Currently, farmed fish are given fish oil, rather than feeding on the algae.
Rothamsted scientists believe genetically modified plants like Camelina have the potential to make fish farming more sustainable and ease the pressure on wild fish populations.