Scientists have applied to plant a group of genetically modified trees on land owned by the Forestry Commission.
University of Southampton researchers want to establish a settlement of GM poplar trees for biofuel research.
The Forestry Commission confirmed the application, but said no decision had been taken yet.
The plantation would be the first attempt to cultivate GM trees in the UK since 1999, when activists destroyed 115 plants in Berkshire.
Campaigners warned that allowing the move to go ahead would be "an unknown and worrying risk" for Britain's ecosystems.
Clare Oxborrow, a GM campaigner for Friends of the Earth, said: "Our concerns with GM trees are even more serious than crops because trees are very long lived.
"They are inherently geared up for spreading seeds and pollen because of they way the reproduce. There's a huge potential for cross-pollination."
University officials were unavailable for comment.