Tesco has pulled the plug on its multi-million pound development in the town.
The proposed Milton Creek site is one of more than 100 new stores across the country which have been scrapped by the supermarket giant.
Plans to build a bridge so pedestrians could walk from the High Street to a new Tesco Extra, as well as an extension to The Forum shopping centre towards the railway line, have also been withdrawn.
The announcement comes after the chain announced yesterday it had suffered its biggest-ever fall in profits.
As a result it says it now plans to sell its Fresh & Easy chain in the US and will focus on revamping existing shops, opening up convenience stores and improving its internet business.
Progress on the Sittingbourne plans had been on hold due to the Highways Agency raising concerns about traffic problems created by the new development at the Key Street roundabout.
John Timothy, regional corporate affairs spokesman, said the changes in customer shopping habits, downturn in the economy and failure to secure planning consent meant it was no longer viable.
He said: “Having spent many years trying to bring this forward, we are disappointed that we have not been able to follow through with our proposals.
“We will actively explore alternative uses for the site and will be working with Swale council to consider how best this land can be put to use.
"In the meantime, we remain committed to serving our customers through our Metro store in The Forum.”