Earlier this year the 29-year-old created Tudors history as the midfielder become the club’s all-time second goalscorer.
But the popular captain, born in the town, has rejected a deal put to him by new manager Sammy Moore.
Parkes has been with the club since 2012, with one year away when he signed for Ebbsfleet United in 2015.
The National League South club have confirmed he is moving on.
“Club captain Jordan Parkes has decided to leave,” they announced.
“He has turned down an offer made to him by the Management team for the forthcoming season.
“We had some great times together over the last six years and he managed to break the club goal scoring record this season.
“We thank Jordan for all of his efforts and wish him well wherever he decides to play next season.”