The expansion, expected to cost between £5m and £15m, is being proposed by current mart operator Harrison and Hetherington (H&H).
It’s proposing a mixed-use development including buildings for retail, housing and leisure use.
The Cumbrian-based firm hopes to completely revamp the mart, just off the A68, as well as building a new development on adjacent land.
The firm’s agent, Galashiels-based Ferguson Planning, said: “The current mart is no longer fit for purpose. Without investment, the auction mart will not survive in the long term.
“Through the proposed plans, H&H Group believes that it can revitalise the mart, the town and provide a significant boost to the agricultural industry in the Borders.”
The plans going before planning chiefs have split the site into four development areas.
The north-east one contains units that will host a mix of rural business uses; the south-east section hosts proposed agricultural education facilities and land; the north-west part is proposed to contain 100-plus residential units along with a hotel and shops; and the south-west section includes the existing auction mart and residential, retail, agriculture and transport facilities.