A colony of newts could hold up the expansion of a Kent airport, according to a campaign group opposing the plans.
Lydd Airport managers say the pond near the runway is no problem
The campaigners say if the runway at Lydd Airport is widened it would mean a pond full of protected Greater Crested Newts having to be partially filled in.
The airport management said the runway at Lydd should not have to be widened - only lengthened.
But they admitted a new landing system could see the exclusion zone around the runway fall 10m into the pond.
Lydd's managers want to expand the airport to be able to carry about two million passengers a year by 2011.
Louise Barton, from the Lydd Airport Action Group, said the newts had protected status which could make the presence of the 2,500-sq-m pond very important.
She said: "The airport needs to make safe the strip around the runway by 150m either side of the centre line of the runway and by doing that it will lead to the need to fill in the large pond which is a main breeding ground for the newts.
"We believe that these protected habitats are sacrosanct and they must not be impinged on by any development."
Protests against expansion at Lydd have been going on for some time
But Lydd Airport managing director Zak Deir said the pond would not be a problem and suggested the campaigners were just raising another issue because of their opposition to the scheme.
Mr Deir said the bigger planes which would use the expanded airport would mean the runway needing to be 294m longer, but no wider.
He said the airport firm would not do anything illegal or anything which would endanger the newts.