An application has been submitted to the Guildhall by the Althorp Estate, home to Earl Spencer, to seek approval for 14 new homes in Northampton.
The homes will be built on part of the site, described as 'vacant scrubland', which was formerly used as tennis courts on the northern extension to Dallington Tennis Club, off Mill Lane.
If given the green light, 14 new homes will be built, but campaigners say building work could have a detrimental impact on a rare species of snake, which breeds near to the pond.
They said: "Being an ex-member of the fishing club I can certainly confirm that there are many snakes in this area and they can be seen swimming across the water in the summertime.
"I have also seen many baby snakes in and around the margins. The main area, which will affect things is that of the upper grass and wooded areas. Snakes reside here and we have actually had them in the garden in the past.
"At present, the area is not open to the public and only for key holders of the fishing club. If this application was to be approved then the associated building disturbances, the new residents and the openness to the general public would undoubtedly contribute to the destruction of the snake habitat."