Construction on a major new £90m shopping centre in York has been delayed due to a rapidly increasing population of breeding newts.
The Monks Cross development was due to open next Christmas but has now been delayed until Easter in 2014 due to a huge rise in newt numbers on the site.
Now all developers and ecologists can do is wait for the newts to emerge from their breeding trenches when the weather improves.
The population of great crested newts has grown on the site by more than 3,000 per cent, from nine to 300 in December, with experts attributing the rise to the wettest summer on recent record. They will now have individually caught and taken in a nearby £300,000 wetland habitat before building work can go-ahead.
The black-and-yellow amphibians are Britain's largest newt species and can reach up to 17cm in length.
Natural England demands developers lay humane traps to catch newts and check them every day during the capture period. The process of rehoming them will only be declared complete when no newts have been caught onsite for five days.
Their transfer to a safe habitat will be led by ecologist Dr Mark Hampton, who claimed the developers may have to wait to clear the site of newts. "They usually start emerging again when temperatures are consistently above five degrees, so at the moment it's just a rather frustrating waiting game," Dr Hampton told The Northern Echo.
Great crested newts are protected under Natural England guidelines. Estimates suggest there are around 400,000 in Britain but their population has declined due to the destruction of their habitats for development.