The two supermarket rivals both want to develop a store in Kelso
A supermarket stand-off in the Borders looks set to last at least six months.
Tesco emerged as preferred bidder for a council-owned site at Pinnaclehill in Kelso late last year.
However, Sainsbury's - which also hopes to develop the area - is in the process of buying adjacent land which would be needed for the development.
Scottish Borders Council has now given Tesco six months to come forward with detailed plans for a new supermarket or it could reconsider bids for the site.
SBC selected Pinnaclehill as its preferred site for a superstore last year, rejecting an alternative location backed by Tesco.
Sainsbury's subsequently submitted full plans for a supermarket on the land, despite the fact that much of it was council-owned and had yet to be sold.
Shortly afterwards, SBC announced Tesco as its preferred bidder for the sale of Pinnaclehill.
The situation appears to have left a stalemate between the two sides.
Sainsbury's has said it will not sell the land it has entered into agreements to buy.
It has also vowed to fight any compulsory purchase orders.
Tesco has said its bid was accepted not only on price but also its ability to deliver an "environmentally friendly store" and "commitment to the community".
A public meeting to discuss the supermarket battle is planned in the town later this month.